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Pediatrics International (2015) 57, 205–209
doi: 10.1111/ped.12551
Original Article
Acoustic improvements after surgical correction in congenital heart disease Chan Uhng Joo, Yoon Mi Choi and Sun Jun Kim Department of Pediatric, Chonbuk National University Medical School, Jeonju, Korea Abstract
Background: Hoarse or asthenic voice is frequently associated with various pediatric cardiac disorders. The aim of this study was to investigate the changes in voice physiology after surgical correction in patients with congenital heart diseases. Methods: We performed voice analysis using induced crying of 40 infants with congenital heart disease (CHD) such as ventricular septal defect (VSD), patent ductus arteriosus (PDA), and atrial septal defect (ASD; 31 girls, 24 boys; mean age, 11 ± 8.9 months). Cries were serially recorded immediately prior to operation, then 1 week, and 1 month after surgical correction, respectively. Acoustic parameters, fundamental frequency (F0), duration of cry, noise to harmonic ratio (NHR), jitter, and shimmer, were extracted using Multi-Dimensional Voice Program™ (MDVP) a computerized speech analysis system. Cries were compared with 30 normal healthy infants of corresponding age. Results: Among the 25 infants with VSD, cry duration, jitter, and shimmer improved after the operation (P < 0.05). F0 and NHR, however, were not significantly different. F0 in patients with PDA improved, but was not statistically significant. The duration of cry, jitter, shimmer, and NHR improved in the PDA group (P < 0.05). The jitter and shimmer parameters improved significantly (P < 0.05), but F0, cry duration, and NHR in patients with ASD did not show any significant changes. Conclusions: Deviated voice patterns in pediatric patients with CHD can normalize after surgical correction. In addition, non-invasive analysis such as MDVP can be used to identify vocal paralysis, even in the early postoperative period.
Key words acoustic analysis, cardiovocal syndrome, crying, patent ductus arteriosus, voice parameter, ventricular septal defect.
Voice changes, including hoarseness, are frequently seen in many pediatric cardiac disorders with left-to-right shunt. Ortner first described patients with severe mitral stenosis who showed symptoms of hoarseness.1 Stocker and Enterline named this constellation of symptoms cardiovocal syndrome.2 The pathogenesis of cardiovocal syndrome has been interpreted as compression or distension of the recurrent laryngeal nerve due to a dilated pulmonary artery or aortic arch.3 Although several authors have reported cardiovocal syndrome in pediatric patients with congenital heart disease (CHD) including atrial septal defect (ASD), ventricular septal defect (VSD), or patent ductus arteriosus (PDA), most of these were case reports.3–6 To the best of our knowledge, there have been no studies describing the changes in acoustic parameters after surgical correction of CHD. This study focused on the changes and reversibility of acoustic parameters such as fundamental frequency (F0), cry duration, jitter, shimmer parameters, and noise to harmonic ratio (NHR) in patients with CHD, before and after surgical correction. We also Correspondence: Sun Jun Kim, MD PhD, Department of Pediatrics, Chonbuk National University Medical School, Jeonju, Jeonbuk, 561180, Korea. Email: [email protected] Received 27 December 2012; revised 8 August 2014; accepted 17 September 2014.
© 2014 Japan Pediatric Society
evaluated the possibility of using a non-invasive technique of voice analysis to detect postoperative complications such as vocal cord paralysis.
Methods Fifty-five patients diagnosed with CHD with left-to-right shunt in the pediatric department of Chonbuk National University Hospital from February 2007 to February 2010 were enrolled in this study (Table 1). The mean patient age at the time of operation was 11 months (±8.9). Thirty infants (13 boys, 17 girls) who visited a well baby clinic for vaccination comprised the control group. The control group consisted of residents from the same metropolitan area (Jeonju, South Korea) with an average age of 8 months (±7.9). Infants who had any abnormalities in orofacial structure, heart disease, rhinitis or upper respiratory infection were excluded from the control group. Induced cries were recorded 10 cm from the infant’s mouth using a microphone (SM 58; Shure, Granjas San Antonio, Mexico D.F., Mexico). Multi-Dimensional Voice Program™ (MDVP; Computerized Speech Lab model 4305, Kay Elemetrics, Pine Brook, NJ, USA) was used to analyze voice parameters. Cries were sampled at least three times per infant: before the operation; 1 week after the operation; and 1 month after the operation. The first cry after stimulus was collected for
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Table 1 CHD subject characteristics Variable M/F Age (months), mean ± SD
VSD group (n = 25) 13/12 11 ± 7.6
PDA group (n = 18) 7/11 11 ± 15.1
ASD group (n = 12) 4/8 11 ± 16.4
Control group (n = 30) 13/17 8 ± 7.9
*P < 0.05. ASD, atrial septal defect; CHD, congenital heart disease; PDA, patent ductus arteriosus; VSD, ventricular septal defect.
analysis. Cries were recorded by a single speech therapist in a soundproof speech therapy room of Chonbuk National University Hospital. Multi-Dimensional Voice Program™ is a computer program that analyzes various aspects of the voice and detects abnormal patterns. MDVP acquires, analyzes, and displays up to 33 voice parameters from a single vocalization. These acoustic parameters provide objective and non-invasive measures of vocal function.7 Among these parameters, we chose F0 and jitter for fundamental variation; and cry duration, shimmer (amplitude), and NHR for noise of voice, according to the recommendations of the Table 2 MDVP acoustic parameters Parameter F0
Unit Hz
Duration Jitter
s %
Shimmer
dB
NHR
Mean Average of extracted period-to-period fundamental frequency Crying duration Evaluation of the very short-term variability of the pitch period Evaluation of the very short-term variability of the peak-to-peak amplitude(loudness) Evaluation of noise presence
Fo, fundamental frequency; MDVP, Multi-Dimensional Voice Program; NHR, noise to harmonic ratio.
European Laryngological Society and our previous experience, to estimate phonation quality (Table 2).7,8 Statistical analysis
Changes in infant cries before operation, 1 week after operation and 1 month after the operation were compared and statistically tested using SPSS 12.0 for Windows (IBM Co., Armonk, NY, USA; P < 0.05). Statistical significance between preoperation and postoperation groups, and the significance between preoperation and normal control groups, was tested using Student t-test. Mann–Whitney test was used for significance between control and postoperation groups.
Results Fundamental variation of voice Very short-term variability of pitch period: Jitter
Jitter is the fundamental frequency variation of voice. Preoperative jitter for infants with VSD was 3.0 ± 1.7%; jitter 1 week postoperatively was 1.5 ± 1.4%; and jitter 1 month postoperatively was 0.9 ± 0.5%, which normalized after surgical correction (P < 0.05; Fig. 1). Among the 18 infants with PDA, preoperative jitter was 3.0 ± 3.1%; jitter 1 week after surgery was 1.4 ± 0.9%; and 1 month postoperatively was 0.8 ± 0.4%, which showed a
Fig. 1 Multi-Dimensional Voice Program radial graph showing improvement in voice parameters after surgical correction in a 1-month-old girl with ventricular septal defect. (a) Before operation; (b) 1 week after operation; (c) 1 month after operation. Gray, normal range; dark, patient parameters. APQ, amplitude perturbation quotient; DSH, degree of sub-harmonics; DUV, degree of voiceless; DVB, degree of voice breaks; Jita, absolute jitter; Jitt, jitter percent; NHR, noise to harmonic ratio; PPQ, pitch perturbation quotient; RAP, relative average perturbation; ShdB, shimmer in dB; Shim, shimmer percent; SPI, soft phonation index; vAm, peak-to-peak amplitude variation; vF0, fundamental frequency variation; VTI, voice turbulence index. © 2014 Japan Pediatric Society
Voice improved after operation in CHD significant improvement after surgery (P < 0.05). For the 12 infants with ASD, preoperative jitter was 2.4 ± 2.2%; 1 week postoperative jitter was 1.7 ± 2.3%; and 1 month postoperative jitter was 0.8 ± 0.5%, showing a significant improvement 1 month after surgery (P < 0.05). Jitter after surgical correction was significantly improved compared with the preoperative level in all groups of infants with CHD (P < 0.05; Table 3). Average frequency variation of voice: F0
Among the 25 infants with VSD, preoperative F0 was 425.0 ± 81.1 Hz; 1 week postoperative F0 was 423.1 ± 97.3 Hz; and 1 month postoperative F0 was 443.0 ± 82.3 Hz. Preoperative F0 in the 18 infants with PDA was 417.3 ± 64.9 Hz; 1 week postoperative F0 was 413.2 ± 82.7 Hz; and 1 month postoperative F0 was 438.5 ± 76.5 Hz (P > 0.05). Among infants with ASD, preoperative F0 was 453.5 ± 53.3 Hz, 1 week postoperative F0 was 421.6 ± 59.6 Hz; and 1 month postoperative F0 was 454.4 ± 52.9 Hz (P > 0.05). Although all patient groups had increased F0 after surgical correction, it was not statistically significant (P > 0.05; Table 3). Duration of cry
Cry duration of infants with VSD, PDA and ASD all increased after surgical correction. For infants with VSD, crying duration preoperatively was 1.8 ± 3.5 s; 1 week after the operation it was 1.9 ± 2.0 s; and 1 month postoperatively it was 2.3 ± 2.9 s, showing a significant increase at 1 month postoperatively compared with preoperatively (P < 0.05). For infants with PDA, preoperative cry duration was 1.4 ± 0.8 s; 1 week postoperative duration was 1.7 ± 2.0 s; and 1 month postoperative duration was 2.0 ± 1.2 s, also showing a significant increase at 1 month postoperatively (P < 0.05). For infants with ASD, preoperative cry duration was 1.4 ± 0.6 s; 1 week postoperative duration was 1.8 ± 0.7 s, and 1 month postoperative cry duration was 1.8 ± 0.7 s, showing an increase in duration after surgical correction, but without statistical significance (P > 0.05; Table 3).
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Intensity variation (amplitude) of voice: Shimmer
For infants with VSD, preoperative shimmer was 0.8 ± 0.4 dB; 1 week postoperative shimmer was 0.5 ± 0.3 dB; and 1 month postoperative shimmer was 0.4 ± 0.2 dB, which showed a significant difference after surgical correction (P < 0.05; Fig. 1). For infants with PDA, preoperative shimmer was 0.7 ± 0.5 dB; 1 week postoperative shimmer was 0.5 ± 0.2 dB; and 1 month postoperative shimmer was 0.3 ± 0.1 dB, showing a significant difference after correction. Among infants with ASD, preoperative shimmer was 0.6 ± 0.3 dB; 1 week postoperative shimmer was 0.6 ± 0.7 dB; and 1 month postoperative shimmer was 0.4 ± 0.2 dB, showing a significant difference after correction (P < 0.05). Shimmer in all CHD patients improved after operation (P > 0.05; Table 3). Noise of voice (noise to harmonic ratio: NHR)
For infants with VSD, preoperative NHR was 0.3 ± 0.3; 1 week postoperative NHR was 0.2 ± 0.1; and 1 month postoperative NHR was 0.2 ± 0.3, showing a significant difference 1 week after surgical correction (P < 0.05; Fig. 1). Among patients with PDA, preoperative NHR was 0.3 ± 0.2; 1 week postoperative NHR was 0.2 ± 0.2; and 1 month postoperative NHR was 0.1 ± 0.1, showing a significant decrease after correction (P < 0.05). In infants with ASD, the preoperative value was 0.3 ± 0.2; 1 week after the operation NHR was 0.3 ± 0.3; and 1 month after operation NHR was 0.2 ± 0.1, which did not show a significant changes (P > 0.05). NHR in infants with VSD and PDA improved after surgical correction, but that of the infants with ASD did not (P < 0.05; Table 3).
Discussion The purpose of this study was to investigate the electroacoustic changes of abnormal voice physiology using the acoustic parameters in pediatric patients with VSD, PDA, and ASD after surgical correction. In CHD with moderate to large amounts of
Table 3 Change in acoustic parameters after corrective surgery (mean ± SD) Before operation Fo (Hz)
Crying duration (s)
Jitter (%)
Shimmer (dB)
NHR
VSD PDA ASD VSD PDA ASD VSD PDA ASD VSD PDA ASD VSD PDA ASD
425.0 ± 81.1 417.3 ± 64.9 453.5 ± 53.3 1.8 ± 3.5 1.4 ± 0.8 1.4 ± 0.6 3.0 ± 1.7 3.0 ± 3.1 2.4 ± 2.2 0.8 ± 0.4 0.7 ± 0.5 0.6 ± 0.3 0.3 ± 0.3 0.3 ± 0.2 0.3 ± 0.2
7 days after operation 423.1 ± 97.3 413.2 ± 82.7 421.6 ± 59.6 1.9 ± 2.0 1.7 ± 2.0 1.8 ± 0.7 1.5 ± 1.4* 1.4 ± 0.9* 1.7 ± 2.3 0.5 ± 0.3* 0.5 ± 0.2* 0.6 ± 0.7 0.2 ± 0.1* 0.2 ± 0.2* 0.3 ± 0.3
30 days after operation 443.0 ± 82.3 438.5 ± 76.5 454.4 ± 52.9 2.3 ± 2.9* 2.0 ± 1.2)* 1.8 ± (0.7) 0.9 ± 0.5)* 0.8 ± 0.4* 0.8 ± 0.5* 0.4 ± 0.2* 0.3 ± 0.1* 0.4 ± 0.2* 0.2 ± 0.3 0.1 ± 0.1* 0.2 ± 0.1
Control group 482.9 ± 51.5 1.4 ± 0.7 0.8 ± 0.3 0.4 ± 0.3
0.1 ± 0.1
*P < 0.05. ASD, atrial septal defect; F0, fundamental frequency; NHR, noise to harmonic ratio; PDA, patent ductus arteriosus; VSD, ventricular septal defect.
© 2014 Japan Pediatric Society
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left-to-right shunt, increased pulmonary blood flow and dilated main pulmonary arteries can compress the recurrent laryngeal nerve externally, and result in a hoarse or asthenic voice called cardiovocal syndrome or Ortner syndrome.2–6,9,10 In addition, it has been suggested that respiratory insufficiency and altered voice duration and intensity may be related to the increased volume of blood in the lungs in left-to-right shunt lesions, caused by decreased pulmonary compliance and increased work of breathing. The present preliminary data show that the acoustic parameters deviated among children with CHD including VSD, ASD, and PDA. Moreover, acoustic variables were conspicuously worse in CHD with left-to-right shunt.8 In our previous study we examined several acoustic parameters such as F0, cry duration, NHR, jitter, and shimmer using MDVP analysis.8 MDVP is a computer program that analyzes various aspects of the voice and detects abnormal voice patterns. MDVP analysis of acoustic parameters provides objective and non-invasive measures of vocal function.7,10–12 MDVP acquires, analyzes and displays up to 33 voice parameters from a single vocalization. Among MDVP parameters, we selected F0 and jitter for fundamental variation, and crying duration, shimmer (amplitude), and NHR for noise of voice according to the recommendation of the European Laryngological Society and our previous experience, to estimate phonation quality in this study (Table 2).7,8 This study focused on the reversibility or even the normalization of these abnormal voice parameters after surgical correction of the cardiac lesion among CHD patients. Jitter and F0 were measured to evaluate the fundamental frequency variation of voice. As compared with the normal control group, these parameters in the preoperative CHD patient group differed significantly (P < 0.05). Jitter markedly improved after surgical correction in all patient groups, especially in the VSD and PDA groups, compared with the ASD patients (P < 0.05, Table 3). We measured shimmer as the index of intensity variation (amplitude) of voice. Shimmer normalized after surgical correction in all groups, especially in the VSD and PDA groups. In recurrent laryngeal nerve dysfunction, unstable vocal cords may exhibit a great amount of noise as compared with the normal condition. We used the NHR parameter for the measurement of voice noisiness. NHR in the VSD and PDA groups improved after surgery, but that of ASD patients did not. In the present study most parameters improved and some parameters completely normalized after correction of CHD (Fig. 1). Enhancement of acoustic parameters was even seen in recovery periods as short as 1 week. Improvement of the parameters continued with longer periods of recovery. These findings suggest that the improvement is due to decreased compression on the recurrent laryngeal nerve by the pulmonary artery and gradual recovery of pulmonary function after operation. The findings also suggest that injuries to the recurrent laryngeal nerves in CHD patients fall into class I or class II according to the Sunderland classification of nerve injuries.13 Cry duration in the VSD, PDA, and ASD groups increased after operation. This finding could be interpreted as improved pulmonary function after correction of the cardiac lesion. © 2014 Japan Pediatric Society
In the early recovery period after open-heart surgery, there are many factors that inhibit voice recovery, such as cauterization stimuli used in the operation, transient ischemic stimuli, prolonged endotracheal intubation, airway secretion, and use of ventilator in the intensive care unit. These can affect recovery of the voice despite normalized pulmonary artery size. Truong et al. reported on the rate of recovery of pediatric vocal fold paralysis after cardiac surgery, with some patients still having persistent vocal fold paralysis at a median follow up of 16.4 months.4 In the present study, although all patients recovered by 6 months, delayed recovery or worsening of findings compared with preoperative voice were observed in 11% of infants with PDA, and in 8% of infants with VSD at 1 month follow up. This appeared to be due to transient vocal cord paralysis related to laryngeal nerve palsy during surgery. For the evaluation of postoperative vocal cord paralysis, most previous studies have used laryngoscopy.14–16 In this study, however, we used a non-invasive method for studying acoustic parameters to examine the change of deviant voice physiology. This non-invasive method can be used as an alternative tool for the evaluation of the changes of deviant voice postoperatively using acoustic parameters. One limitation of this study is that we did not include changes of acoustic parameters at >6 months in patients with CHD. Another limitation was the small number of patients. Despite these limitations, this study has shown that deviated voice parameters can improve progressively with correction of the cardiac lesion. Changes in voice parameters affected by methods of treatment, duration of operation, and relative size of the main pulmonary artery should be evaluated in future studies. Conclusion
Deviated voice in pediatric patients with CDH can normalize after surgical correction. The present data also suggest that noninvasive analysis such as MDVP can be used to identify postoperative vocal cord paralysis, even in the early postoperative period.
Conflict of interest There is no potential conflict of interest relevant to this article to report.
References 1 Ortner N. Recurrenslahmumg bei mitral stenosis. Wien. Klin. Wochenschr. 1897; 10: 753–5. 2 Stocker HH, Enterline HT. Cardio-vocal syndrome: Laryngeal paralysis in intrinsic heart disease. Am. Heart J. 1958; 56: 51–9. 3 Mulpuru SK, Vasavada BC, Punukollu GK et al. Cardiovocal syndrome: A systematic review. Heart Lung Circ. 2008; 17: 1–4. 4 Truong MT, Messner AH, Kerschner JE et al. Pediatric vocal fold paralysis after cardiac surgery: Rate of recovery and sequelae. Otolaryngol. Head Neck Surg. 2007; 137: 780–84. 5 Chan P, Lee CP, Ko JT et al. Cardiovocal (Ortner’s) syndrome left recurrent laryngeal nerve palsy associated with cardiovascular disease. Eur. J. Med. 1992; 1: 492–5. 6 Carpes LF, Kozak FK, Leblanc JG et al. Assessment of vocal fold mobility before and after cardiothoracic surgery in children. Arch. Otolaryngol. Head Neck Surg. 2011; 137: 571–5.
Voice improved after operation in CHD 7 Dejonckere PH, Bradley P, Clemente P et al. A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Guideline elaborated by the Committee on Phoniatrics of the European Laryngological Society (ELS). Eur. Arch. Otorhinolaryngol. 2001; 258: 77–82. 8 Oh JE, Choi YM, Kim SJ et al. Acoustic variations associated with congenital heart disease. Korean J. Pediatr. 2010; 53: 190–94. 9 Hamdan AL, Moukarbel RV, Farhat F et al. Vocal cord paralysis after open-heart surgery. Eur. J. Cardiothorac Surg. 2002; 21: 671–4. 10 Nakahira M, Nakatani H, Takeda T. Left vocal cord paralysis associated with long-standing patent ductus arteriosus. AJNR Am. J. Neuroradiol. 2001; 22: 759–61. 11 Zelcer S, Henri C, Tewfik TL et al. Multidimensional voice program analysis (MDVP) and the diagnosis of pediatric
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13 14
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vocal cord dysfunction. Ann. Allergy Asthma Immunol. 2002; 88: 601–8. An YS, Kim ST, Chung JW. Preoperative voice parameters affect the postoperative speech intelligibility in patients with cochlear implantation. Clin. Exp. Otorhinolaryngol. 2012; 5: 569–72. Sunderland S. The anatomy and physiology of nerve injury. Muscle Nerve 1990; 13: 771–84. Sachdeva R, Hussain E, Moss MM et al. Vocal cord dysfunction and feeding difficulties after pediatric cardiovascular surgery. J. Pediatr. 2007; 151: 312–5. Farrag TY, Samlan RA, Lin FR et al. The utility of evaluating true vocal fold motion before thyroid surgery. Laryngoscope 2006; 116: 235–8. Lacoste L, Karayan J, Lehuedé MS et al. A comparison of direct, indirect, and fiberoptic laryngoscopy to evaluate vocal cord paralysis after thyroid surgery. Thyroid 1996; 6: 17–21.
© 2014 Japan Pediatric Society
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Pediatrics International (2015) 57, 205–209
doi: 10.1111/ped.12551
Original Article
Acoustic improvements after surgical correction in congenital heart disease Chan Uhng Joo, Yoon Mi Choi and Sun Jun Kim Department of Pediatric, Chonbuk National University Medical School, Jeonju, Korea Abstract
Background: Hoarse or asthenic voice is frequently associated with various pediatric cardiac disorders. The aim of this study was to investigate the changes in voice physiology after surgical correction in patients with congenital heart diseases. Methods: We performed voice analysis using induced crying of 40 infants with congenital heart disease (CHD) such as ventricular septal defect (VSD), patent ductus arteriosus (PDA), and atrial septal defect (ASD; 31 girls, 24 boys; mean age, 11 ± 8.9 months). Cries were serially recorded immediately prior to operation, then 1 week, and 1 month after surgical correction, respectively. Acoustic parameters, fundamental frequency (F0), duration of cry, noise to harmonic ratio (NHR), jitter, and shimmer, were extracted using Multi-Dimensional Voice Program™ (MDVP) a computerized speech analysis system. Cries were compared with 30 normal healthy infants of corresponding age. Results: Among the 25 infants with VSD, cry duration, jitter, and shimmer improved after the operation (P < 0.05). F0 and NHR, however, were not significantly different. F0 in patients with PDA improved, but was not statistically significant. The duration of cry, jitter, shimmer, and NHR improved in the PDA group (P < 0.05). The jitter and shimmer parameters improved significantly (P < 0.05), but F0, cry duration, and NHR in patients with ASD did not show any significant changes. Conclusions: Deviated voice patterns in pediatric patients with CHD can normalize after surgical correction. In addition, non-invasive analysis such as MDVP can be used to identify vocal paralysis, even in the early postoperative period.
Key words acoustic analysis, cardiovocal syndrome, crying, patent ductus arteriosus, voice parameter, ventricular septal defect.
Voice changes, including hoarseness, are frequently seen in many pediatric cardiac disorders with left-to-right shunt. Ortner first described patients with severe mitral stenosis who showed symptoms of hoarseness.1 Stocker and Enterline named this constellation of symptoms cardiovocal syndrome.2 The pathogenesis of cardiovocal syndrome has been interpreted as compression or distension of the recurrent laryngeal nerve due to a dilated pulmonary artery or aortic arch.3 Although several authors have reported cardiovocal syndrome in pediatric patients with congenital heart disease (CHD) including atrial septal defect (ASD), ventricular septal defect (VSD), or patent ductus arteriosus (PDA), most of these were case reports.3–6 To the best of our knowledge, there have been no studies describing the changes in acoustic parameters after surgical correction of CHD. This study focused on the changes and reversibility of acoustic parameters such as fundamental frequency (F0), cry duration, jitter, shimmer parameters, and noise to harmonic ratio (NHR) in patients with CHD, before and after surgical correction. We also Correspondence: Sun Jun Kim, MD PhD, Department of Pediatrics, Chonbuk National University Medical School, Jeonju, Jeonbuk, 561180, Korea. Email: [email protected] Received 27 December 2012; revised 8 August 2014; accepted 17 September 2014.
© 2014 Japan Pediatric Society
evaluated the possibility of using a non-invasive technique of voice analysis to detect postoperative complications such as vocal cord paralysis.
Methods Fifty-five patients diagnosed with CHD with left-to-right shunt in the pediatric department of Chonbuk National University Hospital from February 2007 to February 2010 were enrolled in this study (Table 1). The mean patient age at the time of operation was 11 months (±8.9). Thirty infants (13 boys, 17 girls) who visited a well baby clinic for vaccination comprised the control group. The control group consisted of residents from the same metropolitan area (Jeonju, South Korea) with an average age of 8 months (±7.9). Infants who had any abnormalities in orofacial structure, heart disease, rhinitis or upper respiratory infection were excluded from the control group. Induced cries were recorded 10 cm from the infant’s mouth using a microphone (SM 58; Shure, Granjas San Antonio, Mexico D.F., Mexico). Multi-Dimensional Voice Program™ (MDVP; Computerized Speech Lab model 4305, Kay Elemetrics, Pine Brook, NJ, USA) was used to analyze voice parameters. Cries were sampled at least three times per infant: before the operation; 1 week after the operation; and 1 month after the operation. The first cry after stimulus was collected for
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Table 1 CHD subject characteristics Variable M/F Age (months), mean ± SD
VSD group (n = 25) 13/12 11 ± 7.6
PDA group (n = 18) 7/11 11 ± 15.1
ASD group (n = 12) 4/8 11 ± 16.4
Control group (n = 30) 13/17 8 ± 7.9
*P < 0.05. ASD, atrial septal defect; CHD, congenital heart disease; PDA, patent ductus arteriosus; VSD, ventricular septal defect.
analysis. Cries were recorded by a single speech therapist in a soundproof speech therapy room of Chonbuk National University Hospital. Multi-Dimensional Voice Program™ is a computer program that analyzes various aspects of the voice and detects abnormal patterns. MDVP acquires, analyzes, and displays up to 33 voice parameters from a single vocalization. These acoustic parameters provide objective and non-invasive measures of vocal function.7 Among these parameters, we chose F0 and jitter for fundamental variation; and cry duration, shimmer (amplitude), and NHR for noise of voice, according to the recommendations of the Table 2 MDVP acoustic parameters Parameter F0
Unit Hz
Duration Jitter
s %
Shimmer
dB
NHR
Mean Average of extracted period-to-period fundamental frequency Crying duration Evaluation of the very short-term variability of the pitch period Evaluation of the very short-term variability of the peak-to-peak amplitude(loudness) Evaluation of noise presence
Fo, fundamental frequency; MDVP, Multi-Dimensional Voice Program; NHR, noise to harmonic ratio.
European Laryngological Society and our previous experience, to estimate phonation quality (Table 2).7,8 Statistical analysis
Changes in infant cries before operation, 1 week after operation and 1 month after the operation were compared and statistically tested using SPSS 12.0 for Windows (IBM Co., Armonk, NY, USA; P < 0.05). Statistical significance between preoperation and postoperation groups, and the significance between preoperation and normal control groups, was tested using Student t-test. Mann–Whitney test was used for significance between control and postoperation groups.
Results Fundamental variation of voice Very short-term variability of pitch period: Jitter
Jitter is the fundamental frequency variation of voice. Preoperative jitter for infants with VSD was 3.0 ± 1.7%; jitter 1 week postoperatively was 1.5 ± 1.4%; and jitter 1 month postoperatively was 0.9 ± 0.5%, which normalized after surgical correction (P < 0.05; Fig. 1). Among the 18 infants with PDA, preoperative jitter was 3.0 ± 3.1%; jitter 1 week after surgery was 1.4 ± 0.9%; and 1 month postoperatively was 0.8 ± 0.4%, which showed a
Fig. 1 Multi-Dimensional Voice Program radial graph showing improvement in voice parameters after surgical correction in a 1-month-old girl with ventricular septal defect. (a) Before operation; (b) 1 week after operation; (c) 1 month after operation. Gray, normal range; dark, patient parameters. APQ, amplitude perturbation quotient; DSH, degree of sub-harmonics; DUV, degree of voiceless; DVB, degree of voice breaks; Jita, absolute jitter; Jitt, jitter percent; NHR, noise to harmonic ratio; PPQ, pitch perturbation quotient; RAP, relative average perturbation; ShdB, shimmer in dB; Shim, shimmer percent; SPI, soft phonation index; vAm, peak-to-peak amplitude variation; vF0, fundamental frequency variation; VTI, voice turbulence index. © 2014 Japan Pediatric Society
Voice improved after operation in CHD significant improvement after surgery (P < 0.05). For the 12 infants with ASD, preoperative jitter was 2.4 ± 2.2%; 1 week postoperative jitter was 1.7 ± 2.3%; and 1 month postoperative jitter was 0.8 ± 0.5%, showing a significant improvement 1 month after surgery (P < 0.05). Jitter after surgical correction was significantly improved compared with the preoperative level in all groups of infants with CHD (P < 0.05; Table 3). Average frequency variation of voice: F0
Among the 25 infants with VSD, preoperative F0 was 425.0 ± 81.1 Hz; 1 week postoperative F0 was 423.1 ± 97.3 Hz; and 1 month postoperative F0 was 443.0 ± 82.3 Hz. Preoperative F0 in the 18 infants with PDA was 417.3 ± 64.9 Hz; 1 week postoperative F0 was 413.2 ± 82.7 Hz; and 1 month postoperative F0 was 438.5 ± 76.5 Hz (P > 0.05). Among infants with ASD, preoperative F0 was 453.5 ± 53.3 Hz, 1 week postoperative F0 was 421.6 ± 59.6 Hz; and 1 month postoperative F0 was 454.4 ± 52.9 Hz (P > 0.05). Although all patient groups had increased F0 after surgical correction, it was not statistically significant (P > 0.05; Table 3). Duration of cry
Cry duration of infants with VSD, PDA and ASD all increased after surgical correction. For infants with VSD, crying duration preoperatively was 1.8 ± 3.5 s; 1 week after the operation it was 1.9 ± 2.0 s; and 1 month postoperatively it was 2.3 ± 2.9 s, showing a significant increase at 1 month postoperatively compared with preoperatively (P < 0.05). For infants with PDA, preoperative cry duration was 1.4 ± 0.8 s; 1 week postoperative duration was 1.7 ± 2.0 s; and 1 month postoperative duration was 2.0 ± 1.2 s, also showing a significant increase at 1 month postoperatively (P < 0.05). For infants with ASD, preoperative cry duration was 1.4 ± 0.6 s; 1 week postoperative duration was 1.8 ± 0.7 s, and 1 month postoperative cry duration was 1.8 ± 0.7 s, showing an increase in duration after surgical correction, but without statistical significance (P > 0.05; Table 3).
207
Intensity variation (amplitude) of voice: Shimmer
For infants with VSD, preoperative shimmer was 0.8 ± 0.4 dB; 1 week postoperative shimmer was 0.5 ± 0.3 dB; and 1 month postoperative shimmer was 0.4 ± 0.2 dB, which showed a significant difference after surgical correction (P < 0.05; Fig. 1). For infants with PDA, preoperative shimmer was 0.7 ± 0.5 dB; 1 week postoperative shimmer was 0.5 ± 0.2 dB; and 1 month postoperative shimmer was 0.3 ± 0.1 dB, showing a significant difference after correction. Among infants with ASD, preoperative shimmer was 0.6 ± 0.3 dB; 1 week postoperative shimmer was 0.6 ± 0.7 dB; and 1 month postoperative shimmer was 0.4 ± 0.2 dB, showing a significant difference after correction (P < 0.05). Shimmer in all CHD patients improved after operation (P > 0.05; Table 3). Noise of voice (noise to harmonic ratio: NHR)
For infants with VSD, preoperative NHR was 0.3 ± 0.3; 1 week postoperative NHR was 0.2 ± 0.1; and 1 month postoperative NHR was 0.2 ± 0.3, showing a significant difference 1 week after surgical correction (P < 0.05; Fig. 1). Among patients with PDA, preoperative NHR was 0.3 ± 0.2; 1 week postoperative NHR was 0.2 ± 0.2; and 1 month postoperative NHR was 0.1 ± 0.1, showing a significant decrease after correction (P < 0.05). In infants with ASD, the preoperative value was 0.3 ± 0.2; 1 week after the operation NHR was 0.3 ± 0.3; and 1 month after operation NHR was 0.2 ± 0.1, which did not show a significant changes (P > 0.05). NHR in infants with VSD and PDA improved after surgical correction, but that of the infants with ASD did not (P < 0.05; Table 3).
Discussion The purpose of this study was to investigate the electroacoustic changes of abnormal voice physiology using the acoustic parameters in pediatric patients with VSD, PDA, and ASD after surgical correction. In CHD with moderate to large amounts of
Table 3 Change in acoustic parameters after corrective surgery (mean ± SD) Before operation Fo (Hz)
Crying duration (s)
Jitter (%)
Shimmer (dB)
NHR
VSD PDA ASD VSD PDA ASD VSD PDA ASD VSD PDA ASD VSD PDA ASD
425.0 ± 81.1 417.3 ± 64.9 453.5 ± 53.3 1.8 ± 3.5 1.4 ± 0.8 1.4 ± 0.6 3.0 ± 1.7 3.0 ± 3.1 2.4 ± 2.2 0.8 ± 0.4 0.7 ± 0.5 0.6 ± 0.3 0.3 ± 0.3 0.3 ± 0.2 0.3 ± 0.2
7 days after operation 423.1 ± 97.3 413.2 ± 82.7 421.6 ± 59.6 1.9 ± 2.0 1.7 ± 2.0 1.8 ± 0.7 1.5 ± 1.4* 1.4 ± 0.9* 1.7 ± 2.3 0.5 ± 0.3* 0.5 ± 0.2* 0.6 ± 0.7 0.2 ± 0.1* 0.2 ± 0.2* 0.3 ± 0.3
30 days after operation 443.0 ± 82.3 438.5 ± 76.5 454.4 ± 52.9 2.3 ± 2.9* 2.0 ± 1.2)* 1.8 ± (0.7) 0.9 ± 0.5)* 0.8 ± 0.4* 0.8 ± 0.5* 0.4 ± 0.2* 0.3 ± 0.1* 0.4 ± 0.2* 0.2 ± 0.3 0.1 ± 0.1* 0.2 ± 0.1
Control group 482.9 ± 51.5 1.4 ± 0.7 0.8 ± 0.3 0.4 ± 0.3
0.1 ± 0.1
*P < 0.05. ASD, atrial septal defect; F0, fundamental frequency; NHR, noise to harmonic ratio; PDA, patent ductus arteriosus; VSD, ventricular septal defect.
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left-to-right shunt, increased pulmonary blood flow and dilated main pulmonary arteries can compress the recurrent laryngeal nerve externally, and result in a hoarse or asthenic voice called cardiovocal syndrome or Ortner syndrome.2–6,9,10 In addition, it has been suggested that respiratory insufficiency and altered voice duration and intensity may be related to the increased volume of blood in the lungs in left-to-right shunt lesions, caused by decreased pulmonary compliance and increased work of breathing. The present preliminary data show that the acoustic parameters deviated among children with CHD including VSD, ASD, and PDA. Moreover, acoustic variables were conspicuously worse in CHD with left-to-right shunt.8 In our previous study we examined several acoustic parameters such as F0, cry duration, NHR, jitter, and shimmer using MDVP analysis.8 MDVP is a computer program that analyzes various aspects of the voice and detects abnormal voice patterns. MDVP analysis of acoustic parameters provides objective and non-invasive measures of vocal function.7,10–12 MDVP acquires, analyzes and displays up to 33 voice parameters from a single vocalization. Among MDVP parameters, we selected F0 and jitter for fundamental variation, and crying duration, shimmer (amplitude), and NHR for noise of voice according to the recommendation of the European Laryngological Society and our previous experience, to estimate phonation quality in this study (Table 2).7,8 This study focused on the reversibility or even the normalization of these abnormal voice parameters after surgical correction of the cardiac lesion among CHD patients. Jitter and F0 were measured to evaluate the fundamental frequency variation of voice. As compared with the normal control group, these parameters in the preoperative CHD patient group differed significantly (P < 0.05). Jitter markedly improved after surgical correction in all patient groups, especially in the VSD and PDA groups, compared with the ASD patients (P < 0.05, Table 3). We measured shimmer as the index of intensity variation (amplitude) of voice. Shimmer normalized after surgical correction in all groups, especially in the VSD and PDA groups. In recurrent laryngeal nerve dysfunction, unstable vocal cords may exhibit a great amount of noise as compared with the normal condition. We used the NHR parameter for the measurement of voice noisiness. NHR in the VSD and PDA groups improved after surgery, but that of ASD patients did not. In the present study most parameters improved and some parameters completely normalized after correction of CHD (Fig. 1). Enhancement of acoustic parameters was even seen in recovery periods as short as 1 week. Improvement of the parameters continued with longer periods of recovery. These findings suggest that the improvement is due to decreased compression on the recurrent laryngeal nerve by the pulmonary artery and gradual recovery of pulmonary function after operation. The findings also suggest that injuries to the recurrent laryngeal nerves in CHD patients fall into class I or class II according to the Sunderland classification of nerve injuries.13 Cry duration in the VSD, PDA, and ASD groups increased after operation. This finding could be interpreted as improved pulmonary function after correction of the cardiac lesion. © 2014 Japan Pediatric Society
In the early recovery period after open-heart surgery, there are many factors that inhibit voice recovery, such as cauterization stimuli used in the operation, transient ischemic stimuli, prolonged endotracheal intubation, airway secretion, and use of ventilator in the intensive care unit. These can affect recovery of the voice despite normalized pulmonary artery size. Truong et al. reported on the rate of recovery of pediatric vocal fold paralysis after cardiac surgery, with some patients still having persistent vocal fold paralysis at a median follow up of 16.4 months.4 In the present study, although all patients recovered by 6 months, delayed recovery or worsening of findings compared with preoperative voice were observed in 11% of infants with PDA, and in 8% of infants with VSD at 1 month follow up. This appeared to be due to transient vocal cord paralysis related to laryngeal nerve palsy during surgery. For the evaluation of postoperative vocal cord paralysis, most previous studies have used laryngoscopy.14–16 In this study, however, we used a non-invasive method for studying acoustic parameters to examine the change of deviant voice physiology. This non-invasive method can be used as an alternative tool for the evaluation of the changes of deviant voice postoperatively using acoustic parameters. One limitation of this study is that we did not include changes of acoustic parameters at >6 months in patients with CHD. Another limitation was the small number of patients. Despite these limitations, this study has shown that deviated voice parameters can improve progressively with correction of the cardiac lesion. Changes in voice parameters affected by methods of treatment, duration of operation, and relative size of the main pulmonary artery should be evaluated in future studies. Conclusion
Deviated voice in pediatric patients with CDH can normalize after surgical correction. The present data also suggest that noninvasive analysis such as MDVP can be used to identify postoperative vocal cord paralysis, even in the early postoperative period.
Conflict of interest There is no potential conflict of interest relevant to this article to report.
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Voice improved after operation in CHD 7 Dejonckere PH, Bradley P, Clemente P et al. A basic protocol for functional assessment of voice pathology, especially for investigating the efficacy of (phonosurgical) treatments and evaluating new assessment techniques. Guideline elaborated by the Committee on Phoniatrics of the European Laryngological Society (ELS). Eur. Arch. Otorhinolaryngol. 2001; 258: 77–82. 8 Oh JE, Choi YM, Kim SJ et al. Acoustic variations associated with congenital heart disease. Korean J. Pediatr. 2010; 53: 190–94. 9 Hamdan AL, Moukarbel RV, Farhat F et al. Vocal cord paralysis after open-heart surgery. Eur. J. Cardiothorac Surg. 2002; 21: 671–4. 10 Nakahira M, Nakatani H, Takeda T. Left vocal cord paralysis associated with long-standing patent ductus arteriosus. AJNR Am. J. Neuroradiol. 2001; 22: 759–61. 11 Zelcer S, Henri C, Tewfik TL et al. Multidimensional voice program analysis (MDVP) and the diagnosis of pediatric
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