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Fatal potential of supraventricular tachycardia in hypertrophic cardiomyopathy
International Journal of Cardiology 93 (2004) 335 – 337 www.elsevier.com/locate/ijcard
Letter to the Editor
Fatal potential of supraventricular tachycardia in hypertrophic cardiomyopathy Miroslav J. Munclinger a,b,*, Andrew S. Thornton b, Daniel P. Schutte c, Karen Sliwa c a P.O. Box 42769, Abu Dhabi, United Arab Emirates Johannesburg Hospital, University of the Witwatersrand, Johannesburg, South Africa c Baragwanath Hospital, University of the Witwatersrand, Johannesburg, South Africa
b
Received 10 April 2002; accepted 6 May 2002
The potential of supraventricular tachycardia to cause sudden death among patients with hypertrophic cardiomyopathy has been acknowledged for years; however, direct evidence is scarce [1– 3]. Recently, an 18-year-old female suffering from an extreme form of hypertrophic cardiomyopathy without obstruction underwent an electrophysiologic study because of recurrent palpitations and episodes of non-sustained broad QRS tachycardia found during 24-h ambulatory ECG monitoring. Baseline 12-lead ECG showed sinus rhythm with a rate of 88 beats/min. The electrophysiologic study found normal V-A and A-V conduction. Ventricular stimulation failed to induce a ventricular arrhythmia. At that stage, a drive of eight beats with cycle length 500 ms with three subsequent extrastimuli at coupling intervals 260 ms was accidentally delivered to the right atrial appendage and caused a supraventricular tachycardia with cycle length 330 ms (182 beats/min) and an immediate blood pressure drop. The ventricles started to fibrillate 22 s after the onset of the tachycardia while the atria continued with fast regular activity (Fig. 1). Surface ECG documented progressive and significant depression of ST segments in the majority of leads before the onset of ventricular fibrillation (Fig. 2). The ventricular fibrillation and atrial tachycardia were terminated by a single direct current shock of 360 J. This case documents the fatal potential of supraventricular tachycardia in hypertrophic cardiomyopathy. Stafford et al. reported a similar case in 1986 [1]. They
* Corresponding author. Tel.: +971-50-662-2954; fax: +971-2-667-2446. E-mail address: [email protected] (M.J. Munclinger). 0167-5273/$ - see front matter D 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0167-5273(03)00191-8
investigated a 15-year-old male with previous out-ofhospital cardiac arrest. During electrophysiologic study, an episode of atrial fibrillation with fast ventricular response (180 – 190 beats/min) led to ventricular fibrillation 100 s later. Ventricular fibrillation was preceded by ischaemic changes on surface ECG. Furthermore, Sato et al. [2] recently reported an ambulatory ECG recording of a patient who died due to ventricular fibrillation preceded by an episode of sinus tachycardia causing ST segment depressions. Elliot et al. [3] followed a group of 16 patients with a history of ventricular tachycardia or fibrillation for 6 F 4 years and documented that episodes of atrial fibrillation or sinus tachycardia, respectively, preceded an appropriate discharge for polymorphic ventricular tachycardia (documented by stored electrocardiograms) in two out of three patients with implanted ICD. The most likely mechanism of ventricular tachycardia developing as a consequence of a supraventricular tachycardia is myocardial ischaemia. All reported cases, as well as ours, documented electrocardiographic signs of ischaemia before the initiation of ventricular fibrillation. It was shown that atrial fibrillation or fast atrial pacing in patients with extreme hypertrophy causes significant systolic dysfunction with immediate hypotension and cardiac output drop [4]. The alternative mechanism in the case of atrial fibrillation could be supranormal A-V nodal conduction of atrial fibrillation. This case underscores the fact that in patients with significant hypertrophy, especially in those with wall thickness > 30 mm [5], even usually well tolerated haemodynamic changes, e.g. supraventricular or sinus tachycardia, may be fatal by inducing a malignant ventricular arrhythmia [1– 3].
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M.J. Munclinger et al. / International Journal of Cardiology 93 (2004) 335–337
Fig. 1. An intracardiac ECG showing the dissociation of atria and ventricles after the onset of ventricular fibrillation. Surface leads I, aVF, V1 and V6 show the change of supraventricular tachycardia to ventricular fibrillation with corresponding changes of intracardiac ECG recordings. The change from regular activation of the right ventricular apex to fibrillation in channel 27-RVa coincides with the onset of ventricular fibrillation on the surface ECG. The regular fast atrial activity recorded in the right atrial appendage (channel 18-hRA) continues uninterrupted. Similar changes can be observed in electrocardiograms recorded close to the bundle of His (channels 14 – 16).
Fig. 2. A 12-lead ECG showing the change of supraventricular tachycardia into ventricular fibrillation (in the long V1 strip at the bottom) preceded by the development of deep ST segment depressions in all leads but aVR and V1 that exhibit significant ST segment elevations.
M.J. Munclinger et al. / International Journal of Cardiology 93 (2004) 335–337
References [1] Stafford WJ, Trohman RG, Bilsker M, et al. Cardiac arrest in an adolescent with atrial fibrillation and hypertrophic cardiomyopathy. J Am Coll Cardiol 1986;7:701 – 4. [2] Sato M, Takenaka K, Yamashita T, et al. Sudden death during Holter electrocardiographic monitoring in a patient with hypertrophic cardiomyopathy. J Cardiol 1998;31:297 – 303. [3] Elliot PM, Sharma SI, Varnava A, et al. Survival after cardiac arrest or
337
sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol 1999;33:1596 – 601. [4] Madariaga I, Carmona JR, Mateas FR, et al. Supraventricular arrhythmia as the cause of sudden death in hypertrophic cardiomyopathy. Eur Heart J 1994;15:134 – 7. [5] Spirito P, Bellone P, Harris KM, et al. Magnitude of left ventricular hypertrophy and risk of sudden death in hypertrophic cardiomyopathy. N Engl J Med 2000;342:1778 – 85.
Letter to the Editor
Fatal potential of supraventricular tachycardia in hypertrophic cardiomyopathy Miroslav J. Munclinger a,b,*, Andrew S. Thornton b, Daniel P. Schutte c, Karen Sliwa c a P.O. Box 42769, Abu Dhabi, United Arab Emirates Johannesburg Hospital, University of the Witwatersrand, Johannesburg, South Africa c Baragwanath Hospital, University of the Witwatersrand, Johannesburg, South Africa
b
Received 10 April 2002; accepted 6 May 2002
The potential of supraventricular tachycardia to cause sudden death among patients with hypertrophic cardiomyopathy has been acknowledged for years; however, direct evidence is scarce [1– 3]. Recently, an 18-year-old female suffering from an extreme form of hypertrophic cardiomyopathy without obstruction underwent an electrophysiologic study because of recurrent palpitations and episodes of non-sustained broad QRS tachycardia found during 24-h ambulatory ECG monitoring. Baseline 12-lead ECG showed sinus rhythm with a rate of 88 beats/min. The electrophysiologic study found normal V-A and A-V conduction. Ventricular stimulation failed to induce a ventricular arrhythmia. At that stage, a drive of eight beats with cycle length 500 ms with three subsequent extrastimuli at coupling intervals 260 ms was accidentally delivered to the right atrial appendage and caused a supraventricular tachycardia with cycle length 330 ms (182 beats/min) and an immediate blood pressure drop. The ventricles started to fibrillate 22 s after the onset of the tachycardia while the atria continued with fast regular activity (Fig. 1). Surface ECG documented progressive and significant depression of ST segments in the majority of leads before the onset of ventricular fibrillation (Fig. 2). The ventricular fibrillation and atrial tachycardia were terminated by a single direct current shock of 360 J. This case documents the fatal potential of supraventricular tachycardia in hypertrophic cardiomyopathy. Stafford et al. reported a similar case in 1986 [1]. They
* Corresponding author. Tel.: +971-50-662-2954; fax: +971-2-667-2446. E-mail address: [email protected] (M.J. Munclinger). 0167-5273/$ - see front matter D 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0167-5273(03)00191-8
investigated a 15-year-old male with previous out-ofhospital cardiac arrest. During electrophysiologic study, an episode of atrial fibrillation with fast ventricular response (180 – 190 beats/min) led to ventricular fibrillation 100 s later. Ventricular fibrillation was preceded by ischaemic changes on surface ECG. Furthermore, Sato et al. [2] recently reported an ambulatory ECG recording of a patient who died due to ventricular fibrillation preceded by an episode of sinus tachycardia causing ST segment depressions. Elliot et al. [3] followed a group of 16 patients with a history of ventricular tachycardia or fibrillation for 6 F 4 years and documented that episodes of atrial fibrillation or sinus tachycardia, respectively, preceded an appropriate discharge for polymorphic ventricular tachycardia (documented by stored electrocardiograms) in two out of three patients with implanted ICD. The most likely mechanism of ventricular tachycardia developing as a consequence of a supraventricular tachycardia is myocardial ischaemia. All reported cases, as well as ours, documented electrocardiographic signs of ischaemia before the initiation of ventricular fibrillation. It was shown that atrial fibrillation or fast atrial pacing in patients with extreme hypertrophy causes significant systolic dysfunction with immediate hypotension and cardiac output drop [4]. The alternative mechanism in the case of atrial fibrillation could be supranormal A-V nodal conduction of atrial fibrillation. This case underscores the fact that in patients with significant hypertrophy, especially in those with wall thickness > 30 mm [5], even usually well tolerated haemodynamic changes, e.g. supraventricular or sinus tachycardia, may be fatal by inducing a malignant ventricular arrhythmia [1– 3].
336
M.J. Munclinger et al. / International Journal of Cardiology 93 (2004) 335–337
Fig. 1. An intracardiac ECG showing the dissociation of atria and ventricles after the onset of ventricular fibrillation. Surface leads I, aVF, V1 and V6 show the change of supraventricular tachycardia to ventricular fibrillation with corresponding changes of intracardiac ECG recordings. The change from regular activation of the right ventricular apex to fibrillation in channel 27-RVa coincides with the onset of ventricular fibrillation on the surface ECG. The regular fast atrial activity recorded in the right atrial appendage (channel 18-hRA) continues uninterrupted. Similar changes can be observed in electrocardiograms recorded close to the bundle of His (channels 14 – 16).
Fig. 2. A 12-lead ECG showing the change of supraventricular tachycardia into ventricular fibrillation (in the long V1 strip at the bottom) preceded by the development of deep ST segment depressions in all leads but aVR and V1 that exhibit significant ST segment elevations.
M.J. Munclinger et al. / International Journal of Cardiology 93 (2004) 335–337
References [1] Stafford WJ, Trohman RG, Bilsker M, et al. Cardiac arrest in an adolescent with atrial fibrillation and hypertrophic cardiomyopathy. J Am Coll Cardiol 1986;7:701 – 4. [2] Sato M, Takenaka K, Yamashita T, et al. Sudden death during Holter electrocardiographic monitoring in a patient with hypertrophic cardiomyopathy. J Cardiol 1998;31:297 – 303. [3] Elliot PM, Sharma SI, Varnava A, et al. Survival after cardiac arrest or
337
sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol 1999;33:1596 – 601. [4] Madariaga I, Carmona JR, Mateas FR, et al. Supraventricular arrhythmia as the cause of sudden death in hypertrophic cardiomyopathy. Eur Heart J 1994;15:134 – 7. [5] Spirito P, Bellone P, Harris KM, et al. Magnitude of left ventricular hypertrophy and risk of sudden death in hypertrophic cardiomyopathy. N Engl J Med 2000;342:1778 – 85.