FORUM-LETTERS
AMIODARONE
TO THE EDITOR
AND TORSADES
DE POINTES
To the Editor:
The recent articles by Myers et al.’ and Rankin et a1.2 demonstrate the effective and relatively safe use of amiodarone as an antiarrhythmic agent. Indeed the fact that it could be used safely to treat a patient with multifactorially induced torsades de pointes, despite a prolongation of the QT, interval (from 0.68 to 0.72 second), gives a new dimension to the use of amiodarone. We agree with the statement that the absolute value of the QT, interval does not predict the occurrence of torsades de pointes.2 We recently reported three cases of torsades de pointes induced by amiodarone and reviewed all 59 reported cases.3The QT, just before the occurrence of these torsades de pointes ranged from 0.43 to 0.87 second, which illustrates the great variability of this parameter. As in the case reported by Rankin et a1.2a multifactorial origin could be attributed to many of the cases we reviewed such as electrolyte disturbances (12 patients had hypokaliemia) and the concomitant use of other proarrhythmogenic medications. The fact that we found only 59 cases of amiodarone-induced torsades de pointes in the literature, mostly induced by multifactorial causes, and the fact that it can now probably be used to treat particular cases of torsades de pointes, gives a new dimension to a product introduced more than 30 years ago as an antianginal agent. Philippe G Jorens, MD A. Van Den Heuuel, MD Gaston A. Parizel, MD General Hospital Middleheim of Internal Medicine and Cardiology Lindendreef 1 2020 Antwerp, Belgium Paul
Department
the proarrhythmic effects as indeed is also the case with amiodarone-induced torsades de pointesl It is not possible at present to identify which “particular” cases of torsades may be safely treated with amiodarone or to exclude exacerbation of the arrhythmia associated with further QT interval prolongation. It may be that future experience will allay these concerns, but for the present we cannot recommend intravenous amiodarone as firstline treatment of torsades de pointes, particularly as its use may be associated with serious toxicity.3
University
Department
Andrew C. Rankin, MD Stuart D. Pringle, MD Stuart M. Cobbe, MD of Medical Cardiology Glasgow Royal Infirmary Glasgow, Scotland
REFERENCES
1. Jorens PG, Van Den Heuvel PA, Ranquin REF, Van Den Branden FA, Parizel GA. Amiodarone induced torsades de pointes. Report of three cases and review of literature. Acta Cardiol 1989;5:411. 2. Rankin AC, Pringle SD, Cobbe SM. Acute treatment of torsades de pointes with amiodarone: proarrhythmic and antiarrhythmic association of QT prolongation. AM HEARTJ 1990;119:185. 3. Mooss AN, Mohiuddin SM, Hee TT, Esterbrooks DJ, Hilleman DE, Rovang KS, Sketch MH. Efficacy and tolerance of high-dose intravenous amiodarone for recurrent, refractory ventricular tachycardia. Am J Cardiol 1990,65:609.
MALIGNANT PERICARDIAL EFFUSION REFERENCES
1. Myers M, Peter T, Weiss D, Nalos PC, Gang ES, Oseran DS, Mandel WJ. Benefit and risks’of long-term amiodarone therapy for sustained ventricular tachycardia/fibrillation: minimum of three-year follow-up in 145 patients. AM HEARTJ
1990;119:8.
2. Rankin AC, Pringle SD, Cobbe SM. Acute treatment of torsades de pointes with amiodarone: proarrhythmic and antiarrhythmic association of QT prolongation. AM HEARTJ 1990;119:185. 3. Jorens PG, Van Den Heuvel PA, Ranquin REF, Van Den Branden FA, Parizel GA. Amiodarone induced torsades de pointes. Report of three cases and review of literature.’ Acta Cardiol 1989;5:411.
REPLY To the Editor:
We note with interest the comments of Jorens et al. on the efficacy and safety of amiodarone, with particular reference to the low incidence of amiodarone-induced torsades de pointes’ and our recent reported use of amiodarone to treat a patient with this arrhythmia.2 However, we cannot agree with the implication that the successful outcome in this one case allows us to infer that amiodarone “can probably now be used to treat particular cases of torsades de pointes.” This case was presented to illustrate the lack of correlation between the degree of QT interval prolongation and 1482
To the Editor:
We read with interest the article by Hawkins and Vacek in the August 1989 issue of the JOURNAL. The diagnostic accuracy of subxiphoid pericardiotomy is considered by the authors to approach 100% in reference to the work of Little et al.’ However, Little and Ferguson2 reported that results of subxiphoid pericardiotomy failed to prove pericardial malignancy in several of their patients. So they developed an original technique, pericardioscopy, which was first proposed by Santos and Frater3 and appeared to extend the diagnostic yield of the pericardial biopsy when made with a rigid mediastinoscope. According to our preliminary results,4 we focused our attention on patients with suspected malignant pericardial effusion. Surgical pericardioscopy was performed in 18 patients and we would like to offer our experience.5 The diagnostic accuracy with pericardioscopy appeared to be better than that with subxiphoid pericardiotomy: in four of our 18 patients the biopsy guided under direct-view control through the rigid mediastinoscope allowed the diagnosis of metastasis even when results of conventional biopsy (obtained by subxiphoid pericardiotomy) were negative in three out of the four patients and results of cytologic studies on the pericardial fluid were normal in two out of the four patients. However, in one patient pericardioscopy failed to reveal a metastasis on the lateral wall of the left ventricle (subxiphoid biopsy and cytologic findings were negative too); a flexible pericardioscope could have been more efficient for detecting this localization6 Since our report5 on a total of 65 pericardioscopic examinations, we have observed three other patients with negative subxiphoid biopsy and
Volume
120
Number
6, Part
Letters to the Editor
1
positive guided biopsy findings (malignant cells were present in the fluid in only one of the three patients). Pericardioscopy with a rigid mediastinoscope also has the therapeutic advantage of avoiding further constriction. In addition to the relief of an eventual tamponade, better cleaning of the cavity can be achieved especially in cases of hemorrhagic effusion, which is a type of fluid frequently present in those patients. Thus clots can be removed and pericardial adhesions loosened better than with a “blind” aspiration. In conclusion, pericardioscopy brings supplementary advantages in comparison to subxiphoid pericardiotomy alone. Thus we are convinced that subxiphoid pericardiotomy with systematic pericardioscopy is the diagnostic and therapeutic initial “treatment of choice” for malignant effusions.
Departments
A. Millaire, MD G. Ducloux, MD A. Wurtz, MD of Cardiology and Surgery University Hospital 59037 Lille, France
REFERENCES
1. Little AG, Kremser PC, Wade JL, Levett JM, De Meester TR, Skinner DB. Operation for diagnosis and treatment of pericardial effusions. Surgery 1984;96:738-44. 2. Little AG, Ferguson MK. Pericardioscopy as adjunct to pericardial window. Chest 1986;89:53-5. 3. Santos GH, Frater RWM. The subxiphoid approach in the treatment of pericardial effusion. Ann Thorac Surg 1977; 23~467-70. 4. Millaire A, Wurtz A, Brullard B, de Groote P, Marquand A, Tison E. Saudemont A. Ducloux G. Intir&ts de la obricardoscopie’dans les bpanchements pbricardiques. A prop& de 20 patients. Arch Ma1 Coeur 1988;81:1071-6. 5. Millaire A, Wurtz A, Tison E, Ducloux G. Effectiveness of pericardioscopy for etiological diagnosis in 18 patients with suspected malignant pericardial effusion [Abstract]. J Am Co11 Cardiol1989;13:235A. 6. Kondos GT, Rich S, Levitsky S. Flexible fiberoptic pericardioscopy for the diagnosis of pericardial disease. J Am Co11 Cardiol 1986;7:432-4.
1483
tained from the standard subxiphoid approach is diagnostic in the majority of patients. It is unclear whether the small increase in diagnostic sensitivity afforded by the more extensive technique requiring general anesthesia has significant clinical impact on this patient population. Furthermore, the diagnosis made by the standard subxiphoid pericardiotomy is obviously dependent on the biopsy size taken and the degree of digital exploration of the pericardial space with breakdown of adhesions and drainage of loculated fluid. A relatively nonaggressive approach to the standard subxiphoid technique may make pericardioscopy appear somewhat erroneously advantageous. The final and possibly most important difficulty with the technique advocated by the authors of this letter is the limited training and availability of the procedure. A limited subxiphoid pericardiotomy can be performed rapidly by all cardiac and thoracic surgeons and many general surgeons as well. The technique of pericardioscopy is not nearly as widely performed and may perhaps result in increased morbidity and mortality if used by untrained operators. The availability of a trained operator and the necessary equipment may limit the application of pericardioscopy in emergent situations. In summary, we believe that pericardioscopy as an adjunct to subxiphoid pericardiectomy is reasonable in settings where expertise and equipment are available, where the slightly increased diagnostic yield from this technique is likely to be of major importance, and where there is no significant urgency attending the performance of the procedure. We maintain that the limited subxiphoid approach with or without pericardioscopy is superior to either needle drainage or more extensive open surgical techniques for the evaluation and therapy of malignant pericardial effusion. Mid
Section University
James L. Vacek, MD America Heart Institute St. Luke’s Hospital Kansas City, MO. John Hawkins, MD of Cardiovascular Diseases of Kansas Medical Center Kansas City, Kan.
REFERENCE
REPLY
1. Little AG, Ferguson MK. Pericardioscopy cardial window. Chest 1986:89:53-5.
as adjunct to peri-
To the Editor:
We appreciate the comments of Drs. Millaire and Ducloux. We believe that what they describe is an extension and refinement of the technique of the limited surgical subxiphoid procedure for evaluation and treatment of suspected malignant pericardial effusion rather than an alternative. They raise several points supporting our opinion that a limited subxiphoid surgical approach is superior to either a needle pericardiocentesis or more extensive open surgical procedures. It would appear logical that more extensive and direct examination of the pericardial surface and space with a pericardioscope would be likely to provide higher diagnostic yield than blind biopsy. However, several points should be made regarding their technique. Pericardioscopy with a rigid mediastinoscope or a flexible bronchoscope requires general anesthesia, which is not necessary for standard subxiphoid pericardial biopsy and window formation. The improvement in diagnostic yield afforded by this more extensive procedure was actually relatively small based on the larger as yet unreported patient population described by Drs. Millaire and Ducloux and the report of Little and Ferguson.’ It would appear that examination of both pericardial fluid and biopsy material ob-
LATIN AMERICAN IMMIGRANTS-BLOOD DONATION AND TRYPANOSOMA CRUZl TRANSMISSION To the Editor:
Although Trypanosoma cruzi, the agent of Chagas’ disease, is enzootic in the United States, the people at risk of natural transmission by vectors are few, and only three natively acquired cases of Chagas’ disease in humans have been reported from the United States.le3 The situation in Latin America is considerably different, however, and although figures vary from country to country, epidemiologic surveys indicate a significant number of people are infected with T. cruzi in nearly all countries of Central and South America.4* 5 The course of the infection with T. cruzi involves an acute and a chronic stage. Clinical signs and symptoms may not appear in the chronic stage for 10 to 20 years after the short acute stage has passed. These chronically infected individuals, however, can have parasites in their blood stream and hence blood donation
AMIODARONE
TO THE EDITOR
AND TORSADES
DE POINTES
To the Editor:
The recent articles by Myers et al.’ and Rankin et a1.2 demonstrate the effective and relatively safe use of amiodarone as an antiarrhythmic agent. Indeed the fact that it could be used safely to treat a patient with multifactorially induced torsades de pointes, despite a prolongation of the QT, interval (from 0.68 to 0.72 second), gives a new dimension to the use of amiodarone. We agree with the statement that the absolute value of the QT, interval does not predict the occurrence of torsades de pointes.2 We recently reported three cases of torsades de pointes induced by amiodarone and reviewed all 59 reported cases.3The QT, just before the occurrence of these torsades de pointes ranged from 0.43 to 0.87 second, which illustrates the great variability of this parameter. As in the case reported by Rankin et a1.2a multifactorial origin could be attributed to many of the cases we reviewed such as electrolyte disturbances (12 patients had hypokaliemia) and the concomitant use of other proarrhythmogenic medications. The fact that we found only 59 cases of amiodarone-induced torsades de pointes in the literature, mostly induced by multifactorial causes, and the fact that it can now probably be used to treat particular cases of torsades de pointes, gives a new dimension to a product introduced more than 30 years ago as an antianginal agent. Philippe G Jorens, MD A. Van Den Heuuel, MD Gaston A. Parizel, MD General Hospital Middleheim of Internal Medicine and Cardiology Lindendreef 1 2020 Antwerp, Belgium Paul
Department
the proarrhythmic effects as indeed is also the case with amiodarone-induced torsades de pointesl It is not possible at present to identify which “particular” cases of torsades may be safely treated with amiodarone or to exclude exacerbation of the arrhythmia associated with further QT interval prolongation. It may be that future experience will allay these concerns, but for the present we cannot recommend intravenous amiodarone as firstline treatment of torsades de pointes, particularly as its use may be associated with serious toxicity.3
University
Department
Andrew C. Rankin, MD Stuart D. Pringle, MD Stuart M. Cobbe, MD of Medical Cardiology Glasgow Royal Infirmary Glasgow, Scotland
REFERENCES
1. Jorens PG, Van Den Heuvel PA, Ranquin REF, Van Den Branden FA, Parizel GA. Amiodarone induced torsades de pointes. Report of three cases and review of literature. Acta Cardiol 1989;5:411. 2. Rankin AC, Pringle SD, Cobbe SM. Acute treatment of torsades de pointes with amiodarone: proarrhythmic and antiarrhythmic association of QT prolongation. AM HEARTJ 1990;119:185. 3. Mooss AN, Mohiuddin SM, Hee TT, Esterbrooks DJ, Hilleman DE, Rovang KS, Sketch MH. Efficacy and tolerance of high-dose intravenous amiodarone for recurrent, refractory ventricular tachycardia. Am J Cardiol 1990,65:609.
MALIGNANT PERICARDIAL EFFUSION REFERENCES
1. Myers M, Peter T, Weiss D, Nalos PC, Gang ES, Oseran DS, Mandel WJ. Benefit and risks’of long-term amiodarone therapy for sustained ventricular tachycardia/fibrillation: minimum of three-year follow-up in 145 patients. AM HEARTJ
1990;119:8.
2. Rankin AC, Pringle SD, Cobbe SM. Acute treatment of torsades de pointes with amiodarone: proarrhythmic and antiarrhythmic association of QT prolongation. AM HEARTJ 1990;119:185. 3. Jorens PG, Van Den Heuvel PA, Ranquin REF, Van Den Branden FA, Parizel GA. Amiodarone induced torsades de pointes. Report of three cases and review of literature.’ Acta Cardiol 1989;5:411.
REPLY To the Editor:
We note with interest the comments of Jorens et al. on the efficacy and safety of amiodarone, with particular reference to the low incidence of amiodarone-induced torsades de pointes’ and our recent reported use of amiodarone to treat a patient with this arrhythmia.2 However, we cannot agree with the implication that the successful outcome in this one case allows us to infer that amiodarone “can probably now be used to treat particular cases of torsades de pointes.” This case was presented to illustrate the lack of correlation between the degree of QT interval prolongation and 1482
To the Editor:
We read with interest the article by Hawkins and Vacek in the August 1989 issue of the JOURNAL. The diagnostic accuracy of subxiphoid pericardiotomy is considered by the authors to approach 100% in reference to the work of Little et al.’ However, Little and Ferguson2 reported that results of subxiphoid pericardiotomy failed to prove pericardial malignancy in several of their patients. So they developed an original technique, pericardioscopy, which was first proposed by Santos and Frater3 and appeared to extend the diagnostic yield of the pericardial biopsy when made with a rigid mediastinoscope. According to our preliminary results,4 we focused our attention on patients with suspected malignant pericardial effusion. Surgical pericardioscopy was performed in 18 patients and we would like to offer our experience.5 The diagnostic accuracy with pericardioscopy appeared to be better than that with subxiphoid pericardiotomy: in four of our 18 patients the biopsy guided under direct-view control through the rigid mediastinoscope allowed the diagnosis of metastasis even when results of conventional biopsy (obtained by subxiphoid pericardiotomy) were negative in three out of the four patients and results of cytologic studies on the pericardial fluid were normal in two out of the four patients. However, in one patient pericardioscopy failed to reveal a metastasis on the lateral wall of the left ventricle (subxiphoid biopsy and cytologic findings were negative too); a flexible pericardioscope could have been more efficient for detecting this localization6 Since our report5 on a total of 65 pericardioscopic examinations, we have observed three other patients with negative subxiphoid biopsy and
Volume
120
Number
6, Part
Letters to the Editor
1
positive guided biopsy findings (malignant cells were present in the fluid in only one of the three patients). Pericardioscopy with a rigid mediastinoscope also has the therapeutic advantage of avoiding further constriction. In addition to the relief of an eventual tamponade, better cleaning of the cavity can be achieved especially in cases of hemorrhagic effusion, which is a type of fluid frequently present in those patients. Thus clots can be removed and pericardial adhesions loosened better than with a “blind” aspiration. In conclusion, pericardioscopy brings supplementary advantages in comparison to subxiphoid pericardiotomy alone. Thus we are convinced that subxiphoid pericardiotomy with systematic pericardioscopy is the diagnostic and therapeutic initial “treatment of choice” for malignant effusions.
Departments
A. Millaire, MD G. Ducloux, MD A. Wurtz, MD of Cardiology and Surgery University Hospital 59037 Lille, France
REFERENCES
1. Little AG, Kremser PC, Wade JL, Levett JM, De Meester TR, Skinner DB. Operation for diagnosis and treatment of pericardial effusions. Surgery 1984;96:738-44. 2. Little AG, Ferguson MK. Pericardioscopy as adjunct to pericardial window. Chest 1986;89:53-5. 3. Santos GH, Frater RWM. The subxiphoid approach in the treatment of pericardial effusion. Ann Thorac Surg 1977; 23~467-70. 4. Millaire A, Wurtz A, Brullard B, de Groote P, Marquand A, Tison E. Saudemont A. Ducloux G. Intir&ts de la obricardoscopie’dans les bpanchements pbricardiques. A prop& de 20 patients. Arch Ma1 Coeur 1988;81:1071-6. 5. Millaire A, Wurtz A, Tison E, Ducloux G. Effectiveness of pericardioscopy for etiological diagnosis in 18 patients with suspected malignant pericardial effusion [Abstract]. J Am Co11 Cardiol1989;13:235A. 6. Kondos GT, Rich S, Levitsky S. Flexible fiberoptic pericardioscopy for the diagnosis of pericardial disease. J Am Co11 Cardiol 1986;7:432-4.
1483
tained from the standard subxiphoid approach is diagnostic in the majority of patients. It is unclear whether the small increase in diagnostic sensitivity afforded by the more extensive technique requiring general anesthesia has significant clinical impact on this patient population. Furthermore, the diagnosis made by the standard subxiphoid pericardiotomy is obviously dependent on the biopsy size taken and the degree of digital exploration of the pericardial space with breakdown of adhesions and drainage of loculated fluid. A relatively nonaggressive approach to the standard subxiphoid technique may make pericardioscopy appear somewhat erroneously advantageous. The final and possibly most important difficulty with the technique advocated by the authors of this letter is the limited training and availability of the procedure. A limited subxiphoid pericardiotomy can be performed rapidly by all cardiac and thoracic surgeons and many general surgeons as well. The technique of pericardioscopy is not nearly as widely performed and may perhaps result in increased morbidity and mortality if used by untrained operators. The availability of a trained operator and the necessary equipment may limit the application of pericardioscopy in emergent situations. In summary, we believe that pericardioscopy as an adjunct to subxiphoid pericardiectomy is reasonable in settings where expertise and equipment are available, where the slightly increased diagnostic yield from this technique is likely to be of major importance, and where there is no significant urgency attending the performance of the procedure. We maintain that the limited subxiphoid approach with or without pericardioscopy is superior to either needle drainage or more extensive open surgical techniques for the evaluation and therapy of malignant pericardial effusion. Mid
Section University
James L. Vacek, MD America Heart Institute St. Luke’s Hospital Kansas City, MO. John Hawkins, MD of Cardiovascular Diseases of Kansas Medical Center Kansas City, Kan.
REFERENCE
REPLY
1. Little AG, Ferguson MK. Pericardioscopy cardial window. Chest 1986:89:53-5.
as adjunct to peri-
To the Editor:
We appreciate the comments of Drs. Millaire and Ducloux. We believe that what they describe is an extension and refinement of the technique of the limited surgical subxiphoid procedure for evaluation and treatment of suspected malignant pericardial effusion rather than an alternative. They raise several points supporting our opinion that a limited subxiphoid surgical approach is superior to either a needle pericardiocentesis or more extensive open surgical procedures. It would appear logical that more extensive and direct examination of the pericardial surface and space with a pericardioscope would be likely to provide higher diagnostic yield than blind biopsy. However, several points should be made regarding their technique. Pericardioscopy with a rigid mediastinoscope or a flexible bronchoscope requires general anesthesia, which is not necessary for standard subxiphoid pericardial biopsy and window formation. The improvement in diagnostic yield afforded by this more extensive procedure was actually relatively small based on the larger as yet unreported patient population described by Drs. Millaire and Ducloux and the report of Little and Ferguson.’ It would appear that examination of both pericardial fluid and biopsy material ob-
LATIN AMERICAN IMMIGRANTS-BLOOD DONATION AND TRYPANOSOMA CRUZl TRANSMISSION To the Editor:
Although Trypanosoma cruzi, the agent of Chagas’ disease, is enzootic in the United States, the people at risk of natural transmission by vectors are few, and only three natively acquired cases of Chagas’ disease in humans have been reported from the United States.le3 The situation in Latin America is considerably different, however, and although figures vary from country to country, epidemiologic surveys indicate a significant number of people are infected with T. cruzi in nearly all countries of Central and South America.4* 5 The course of the infection with T. cruzi involves an acute and a chronic stage. Clinical signs and symptoms may not appear in the chronic stage for 10 to 20 years after the short acute stage has passed. These chronically infected individuals, however, can have parasites in their blood stream and hence blood donation
