Tachycardia induced myocardial dysfunction. A reversible phenomenon?

Abstract

SUMMARY Four patients with myocardial dysfunction related to tachycardia underwent electrophysiological studies, which showed a re-entrant supraventricular tachycardia using an accessory atrioventricular connexion. Serial assessment of left ventricular function by echocardiography before and after control of the tachycardia indicated a variable degree of reversibility. Endomyocardial biopsy in two patients detected non-specific histological changes. Because of the possible role of ischaemia in this condition effective control of prolonged tachycardia is needed to prevent deterioration of myocardial function.Paroxysmal supraventricular tachycardia is usually well tolerated in the absence of underlying impairment of cardiac function.1-3 There are, however, published reports of patients with chronic or frequent episodes of supraventricular tachycardia who present with symptoms and with clinical and radiological signs of congestive cardiac failure.4-9 The patients in these reported cases were in general young, often in the paediatric age group. Many were without underlying cardiac disease, and with control of the tachyarrhythmia the symptoms and signs of congestive heart failure resolved. Detailed assessment of the mechanism of the arrhythmia and accurate serial determination of left ventricular function before and after the resolution of congestive heart failure, as A 16 year old girl had an episode of syncope which caused no personal injury. Supraventricular tachycardia (rate 160 beats/minute) was noted at the local hospital, and a chest x ray film showed cardiomegaly. She had been asymptomatic up to the time of the accident, and there was no history suggesting a recent viral illness or excessive alcohol consumption. Four weeks later she was referred to the Mayo Clinic with persistent tachycardia. She had remained asymptomatic. Chest x ray films showed cardiomegaly without pulmonary congestion, and an electrocardiogram showed a narrow complex supraventricular tachycardia (rate 150 beats/minute) with a long ventriculoatrial interval (Fig. 1). The P waves were negative in leads II, III, and aVF, and the ratio of the interval between the R wave and the retrograde P wave to the cycle length was >0*5, suggesting the permanent type of reciprocating junctional tachycardia. 12 The left ventricular ejection fraction measured during tachycardia by echocardiography (Fig. 2)

Heart Failure and Sudden Death in Patients With Tachycardia-Induced Cardiomyopathy and Recurrent Tachycardia

“…Biopsies of 2 young patients with TIC showed mild hypertrophy and focal interstitial fibrosis in 1 patient and mild to moderate cellular hypertrophy with focal degenerative changes and mild to moderate interstitial edema in the other. 1 Persistent ultrastructural changes in animal models suggest other possibilities.…”

Changes in left ventricular volume, mass, and function during the development and regression of supraventricular tachycardia-induced cardiomyopathy. Disparity between recovery of systolic versus diastolic function.

“…[2][3][4][5][6][7][8]32 However, none of these clinical studies identified the mechanisms responsible for the changes in LV volume and ejection fraction. Data from our current study suggest that once the hemodynamic burden of chronic tachycardia was removed, improvement in systolic function was associated with the development of LV hypertrophy and a consequent decrease in afterload.…”

Diagnostic Approach and Treatment Strategy in Tachycardia‐induced Cardiomyopathy

“…2 Tachycardia-induced cardiomyopathy is highly dependent on the heart rate, and that higher heart rates induce TIC earlier. 3 -5 Adequate control of heart rate 6,7 or restoration of sinus rhythm 8,9 is necessary for improving cardiac function and symptoms.…”