© 2015, Wiley Periodicals, Inc. DOI: 10.1111/echo.12987
Echocardiography
Left Atrial Dysfunction Assessed by Two-Dimensional Speckle Tracking Echocardiography in Patients with Impaired Left Ventricular Ejection Fraction and SleepDisordered Breathing ska Karolina, M.D., Błaz_ ej W. Michalski, M.D., Ph.D., Barbara Uznan ska-Loch, Dawid Miskowiec, M.D., Kupczyn M.D., Ph.D., Małgorzata Kurpesa, M.D., Ph.D., Jarosław D. Kasprzak, M.D., Ph.D., and Piotr Lipiec, M.D., Ph.D. Department of Cardiology, Medical University of Lodz, Lodz, Poland
Aims: To evaluate the relationship between left atrial (LA) structure and deformation obtained by twodimensional speckle tracking echocardiography (2DSTE): peak longitudinal systolic strain (LAs), peak longitudinal systolic strain rate (LAS-SR), peak longitudinal early diastolic strain rate (LAE-SR), peak longitudinal late diastolic strain rate (LAA-SR), and sleep-disordered breathing (SDB) estimated by means of apnea–hypopnea index (eAHI). Methods: Thirty-two individuals with ischemic heart disease (IHD) and impaired left ventricular ejection fraction (EF < 50%) were included in the study. LA function was assessed using 2DSTE. eAHI index was calculated by means of the 24-hour ambulatory Holter electrocardiogram monitoring. Patients were categorized into two subgroups: SDB group (eAHI ≥ 15; n = 15) and non-SDB group (eAHI < 15; n = 17). Results: All 2DSTE parameters were decreased in the SDB group: LAS-SR (0.90 [0.60–1.25] 1/sec vs. 1.25 [1.00–1.27] 1/sec, P = 0.043), LAE-SR (0.76 0.49 1/sec vs. 1.18 0.55 1/sec, P = 0.033), and LAA-SR (1.26 0.71 1/sec vs. 1.48 0.75 1/sec, P = 0.049). The eAHI was negatively correlated with LA reservoir function: LAS (r = 0.53, P = 0.002) and LAS-SR (r = 0.47, P = 0.006), while it is positively correlated with LAE-SR (r = 0.67, P < 0.001) and LAA-SR (r = 0.46, P = 0.009). Moreover, SDB severity was an independent predictor of impaired LA compliance (P = 0.016) and conduit function (P = 0.002) in multivariate linear regression model, even after adjustment for age, BMI, gender, LV systolic (EF), and diastolic (E/e0 ) function and comorbidities. Conclusions: LA dysfunction and remodeling assessed using 2DSTE in patients with impaired systolic LV function, and IHD is influenced by the severity of sleep apnea independently from LV function. (Echocardiography 2016;33:38–45) Key words: left atrium, strain, strain rate imaging, ischemic heart disease, systolic function, diastolic function
Sleep-disordered breathing (SDB) is a relatively common condition, with incidence 2–4% in the general middle-aged population,1 and approximately 20–30% in the elderly.2 There are three main forms of SDB: obstructive sleep apnea (OSA), central sleep apnea (CSA), and mixed form. The apnea and hypopnea index (AHI) is widely used to indicate the severity of SDB.3,4 It represents the mean number of apneic and hypopneic events per hour of sleep.3 Polysomnography (PSG) remains the “gold standard” in diagnosis of SDB.3 However, Address for correspondence and reprint requests: Dawid Miskowiec, M.D., Department of Cardiology, Medical University of Lodz, Kniaziewicza Street 1/5, 91-347, Lodz, Poland. Fax: +4842-653-9909; E-mail: [email protected]
38
this method requires highly qualified staff and hospital overnight stay and is thus time- and cost-consuming. New simplified, fast and costeffective methods of identification of individuals with SDB are currently widely investigated. One of them is a relatively simple technique based on the analysis of electrocardiographic (ECG) records obtained during patient’s sleep with the use of Lifescreen Apnea software (Delmar Reynolds). It enables calculation of estimated AHI (eAHI), based on the breathing activity as well as modulatory influence of central nervous system on SDB. ECG signal amplitude is altered by respiration, while the heart rate variability (HRV) is modulated by the autonomic nervous system. In summary, the sleep apnea can be identified automatically by characteristic cyclic variation in heart
Left Atrial Dysfunction and Sleep-Disordered Breathing
rate and changes in the amplitude of the ECG, described in detail5,6 and validated with PSG by other authors.7 SDB increases the risk of cardiovascular events, especially in the population with diagnosed heart disease8–10 and is associated with numerous pathologies such as sympathetic nervous system activation,11,12 increased systematic oxidative stress12,13 as well as inflammation12,14 adversely affecting outcomes. SDB has also been shown to influence left atrial function assessed by standard morphometric parameters.15 However, the data regarding the relationship between SDB and LA function evaluated by new echocardiographic techniques such as two-dimensional speckle tracking echocardiography (2DSTE) is still limited. We sought to examine the relationship between eAHI and LA parameters obtained with 2DSTE (peak longitudinal systolic LA strain, peak systolic LA strain rate, peak early diastolic LA strain rate, peak late diastolic LA strain) and standard structural LA parameters (LA ejection fraction, LA volume, LA diameters and LA area) in patients with stable coronary artery disease with impaired (EF < 50%) LV ejection fraction. Material and Methods: Population: Study group was composed of 32 patients with stable ischemic heart disease and impaired LVEF (LVEF < 50%) who were admitted to our department between January 2014 and November 2014. Exclusion criteria were the following: atrial fibrillation, atrial flutter, third degree atrioventricular block, ventricular or supraventricular tachycardia, moderate or severe valvular heart disease, chronic obstructive pulmonary disease or asthma, unstable angina, recent myocardial infarction (
Echocardiography
Left Atrial Dysfunction Assessed by Two-Dimensional Speckle Tracking Echocardiography in Patients with Impaired Left Ventricular Ejection Fraction and SleepDisordered Breathing ska Karolina, M.D., Błaz_ ej W. Michalski, M.D., Ph.D., Barbara Uznan ska-Loch, Dawid Miskowiec, M.D., Kupczyn M.D., Ph.D., Małgorzata Kurpesa, M.D., Ph.D., Jarosław D. Kasprzak, M.D., Ph.D., and Piotr Lipiec, M.D., Ph.D. Department of Cardiology, Medical University of Lodz, Lodz, Poland
Aims: To evaluate the relationship between left atrial (LA) structure and deformation obtained by twodimensional speckle tracking echocardiography (2DSTE): peak longitudinal systolic strain (LAs), peak longitudinal systolic strain rate (LAS-SR), peak longitudinal early diastolic strain rate (LAE-SR), peak longitudinal late diastolic strain rate (LAA-SR), and sleep-disordered breathing (SDB) estimated by means of apnea–hypopnea index (eAHI). Methods: Thirty-two individuals with ischemic heart disease (IHD) and impaired left ventricular ejection fraction (EF < 50%) were included in the study. LA function was assessed using 2DSTE. eAHI index was calculated by means of the 24-hour ambulatory Holter electrocardiogram monitoring. Patients were categorized into two subgroups: SDB group (eAHI ≥ 15; n = 15) and non-SDB group (eAHI < 15; n = 17). Results: All 2DSTE parameters were decreased in the SDB group: LAS-SR (0.90 [0.60–1.25] 1/sec vs. 1.25 [1.00–1.27] 1/sec, P = 0.043), LAE-SR (0.76 0.49 1/sec vs. 1.18 0.55 1/sec, P = 0.033), and LAA-SR (1.26 0.71 1/sec vs. 1.48 0.75 1/sec, P = 0.049). The eAHI was negatively correlated with LA reservoir function: LAS (r = 0.53, P = 0.002) and LAS-SR (r = 0.47, P = 0.006), while it is positively correlated with LAE-SR (r = 0.67, P < 0.001) and LAA-SR (r = 0.46, P = 0.009). Moreover, SDB severity was an independent predictor of impaired LA compliance (P = 0.016) and conduit function (P = 0.002) in multivariate linear regression model, even after adjustment for age, BMI, gender, LV systolic (EF), and diastolic (E/e0 ) function and comorbidities. Conclusions: LA dysfunction and remodeling assessed using 2DSTE in patients with impaired systolic LV function, and IHD is influenced by the severity of sleep apnea independently from LV function. (Echocardiography 2016;33:38–45) Key words: left atrium, strain, strain rate imaging, ischemic heart disease, systolic function, diastolic function
Sleep-disordered breathing (SDB) is a relatively common condition, with incidence 2–4% in the general middle-aged population,1 and approximately 20–30% in the elderly.2 There are three main forms of SDB: obstructive sleep apnea (OSA), central sleep apnea (CSA), and mixed form. The apnea and hypopnea index (AHI) is widely used to indicate the severity of SDB.3,4 It represents the mean number of apneic and hypopneic events per hour of sleep.3 Polysomnography (PSG) remains the “gold standard” in diagnosis of SDB.3 However, Address for correspondence and reprint requests: Dawid Miskowiec, M.D., Department of Cardiology, Medical University of Lodz, Kniaziewicza Street 1/5, 91-347, Lodz, Poland. Fax: +4842-653-9909; E-mail: [email protected]
38
this method requires highly qualified staff and hospital overnight stay and is thus time- and cost-consuming. New simplified, fast and costeffective methods of identification of individuals with SDB are currently widely investigated. One of them is a relatively simple technique based on the analysis of electrocardiographic (ECG) records obtained during patient’s sleep with the use of Lifescreen Apnea software (Delmar Reynolds). It enables calculation of estimated AHI (eAHI), based on the breathing activity as well as modulatory influence of central nervous system on SDB. ECG signal amplitude is altered by respiration, while the heart rate variability (HRV) is modulated by the autonomic nervous system. In summary, the sleep apnea can be identified automatically by characteristic cyclic variation in heart
Left Atrial Dysfunction and Sleep-Disordered Breathing
rate and changes in the amplitude of the ECG, described in detail5,6 and validated with PSG by other authors.7 SDB increases the risk of cardiovascular events, especially in the population with diagnosed heart disease8–10 and is associated with numerous pathologies such as sympathetic nervous system activation,11,12 increased systematic oxidative stress12,13 as well as inflammation12,14 adversely affecting outcomes. SDB has also been shown to influence left atrial function assessed by standard morphometric parameters.15 However, the data regarding the relationship between SDB and LA function evaluated by new echocardiographic techniques such as two-dimensional speckle tracking echocardiography (2DSTE) is still limited. We sought to examine the relationship between eAHI and LA parameters obtained with 2DSTE (peak longitudinal systolic LA strain, peak systolic LA strain rate, peak early diastolic LA strain rate, peak late diastolic LA strain) and standard structural LA parameters (LA ejection fraction, LA volume, LA diameters and LA area) in patients with stable coronary artery disease with impaired (EF < 50%) LV ejection fraction. Material and Methods: Population: Study group was composed of 32 patients with stable ischemic heart disease and impaired LVEF (LVEF < 50%) who were admitted to our department between January 2014 and November 2014. Exclusion criteria were the following: atrial fibrillation, atrial flutter, third degree atrioventricular block, ventricular or supraventricular tachycardia, moderate or severe valvular heart disease, chronic obstructive pulmonary disease or asthma, unstable angina, recent myocardial infarction (
