Cardiac arrest in an adolescent with atrial fibrillation and hypertrophic cardiomyopathy

Abstract

A 15 year old youth, who presented with out-of-hospital cardiac arrest due to documented ventricular fibrillation, was found to have nonobstructive hypertrophic cardiomyopathy. Electrophysiologic study demonstrated inducible sustained atrial fibrillation with a rapid ventricular response. This rhythm, associated with hypotension and evidence of myocardial ischemia, spontaneously degenerated into ventricular fibrillation. No ventricular arrhythmias were inducible by programmed ventricular stimulation. Therapy with metoprolol and verapamil slowed the ventricular rate during atrial fibrillation and maintained hemodynamic stability, both during follow-up electrophysiologic study and during a subsequent spontaneous episode.

Long-term results of dual-chamber (DDD) pacing in obstructive hypertrophic cardiomyopathy. Evidence for progressive symptomatic and hemodynamic improvement and reduction of left ventricular hypertrophy.

“…Atrial fibrillation is the most common supraventricular arrhythmia recorded in HCM.17,l8 Sudden loss of atrial contribution, tachycardia, and irregular LV filling and emptying can have devastating hemodynamic consequences and precipitate sudden death. [17][18][19] We have previously reported that radiofrequency ablation of the AV node coupled with rate-responsive pacing results in satisfactory symptomatic and hemodynamic outcome in HCM patients with atrial fibrillation.20 Although the relief of LVOT obstruction and consequently, reduction of mitral regurgitation and of left atrial pressures may help prevent atrial arrhythmias, our study did not provide evidence to support this. Conversely, ventricular pacing with retrograde atrial activation due to inability to sense P waves satisfactorily could precipitate atrial fibrillation.…”

Impact of Atrial Fibrillation on the Clinical Course of Hypertrophic Cardiomyopathy

“…6 -11 Early observational studies (confined largely to patients with obstruction) emphasized the association of AF onset with severe acute clinical deterioration. 6,7 Conversely, a more recent study reported no difference in mortality among patients with AF compared with an HCM control group in sinus rhythm. 10 However, the latter investigation was based largely on highly selected patients at a tertiary referral center, 4,5 and the deleterious impact of AF may have been obscured by the low survival rate in control patients with sinus rhythm.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] However, studies regarding long-term prognosis of AF in HCM patients have been sparse and often conflicting, with some reports suggesting a generally unfavorable prognosis associated with this arrhythmia [5][6][7][8][9] and others indicating a relatively benign course. 10,11 Thus, many crucial issues regarding the determinants and clinical impact of AF on HCM patients remain unresolved; therefore, the present investigation was undertaken in our community-based population, including the largest series of HCM patients with AF assembled to date.…”

Genome editing with CRISPR/Cas9 in postnatal mice corrects PRKAG2 cardiac syndrome

“…2D and Doppler echocardiographic measurements, including left ventricular maximal wall thickness, left atrial and left ventricular dimensions at end-systole and end-diastole were performed in accordance with previously published methods [40]. The left ventricular ejection fraction was calculated according to Simpson's method [41]. When appropriate, peak resting and/or exercise-induced left ventricular outflow tract obstruction, were estimated by continuous-wave Doppler at rest and/or during exercise (bicycle).…”