Heart Rate Turbulence and Clinical Prognosis in Hypertrophic Cardiomyopathy and Myocardial Infarction

Abstract

eart rate turbulence (HRT) represents short-term fluctuations in sinus cycle length after a single ventricular premature complex (VPC). Normally, HRT comprises sinus rate acceleration during several beats immediately following a VPC and the subsequent deceleration back to the baseline before the 20th beat. 1,2 It is now believed that HRT is principally triggered by underlying physiological alterations of cardiac autonomic regulation; a VPC preceded by a short coupling interval results in a sudden drop in blood pressure because of insufficient ventricular filling, with subsequent transient loss of vagal efferent activity leading to sinus rate acceleration. 3,4 The early acceleration and late deceleration in sinus cycle length following a VPC are termed the HRT onset and HRT slope, respectively, and are each currently being used in the assessment of HRT. Recently, these variables were reported to be powerful independent predictors of the clinical prognosis in patients with myocardial infarction (MI). [5][6][7] However, data for patients with hypertrophic cardiomyopathy (HCM) are not available, so the purpose of the present Circulation Journal Vol.67, July 2003 study was to determine these variables in HCM patients and correlate them with the clinical prognosis. Methods Study PopulationWe studied 104 consecutive ambulatory HCM patients, 44 MI patients and 56 normal controls who were treated at or referred to Matsushita Memorial Hospital during the period of April 2000 to March 2002. All subjects had regular sinus rhythm and were clinically stable. The MI patients and controls were matched to the HCM patients with regard to age and gender distribution. The diagnosis of HCM was based on echocardiographic demonstration of left ventricular (LV) hypertrophy with end-diastolic wall thickness ≥15 mm and LV end-diastolic dimensions ≤55 mm, in the absence of any cardiac or systemic disorder that causes LV hypertrophy. 8,9 The HCM patient group consisted of 83 men and 21 women with a mean age of 56±13 years; of them 8 had apical hypertrophy, 12 had a family history of sudden death, 17 had episodes of syncope, 34 had ventricular tachycardia defined as 3 or more consecutive VPCs with a frequency >120 beats/min. The maximum LV wall thickness was 22±3 mm and LV fractional shortening was 41±8% on echocardiogram. Eight patients had a Dopplercalculated resting left ventricular outflow tract gradient of at least 30 mmHg. The class of heart failure was New York Heart Association (NYHA) I in 65 patients, II in 38 patients and III in 1 patient. Toshiro Kuribayashi, MD**; Hiroki Sugihara, MD Short-term fluctuations in sinus cycle length after a single ventricular premature complex (VPC) have attracted considerable interest and has been termed heart rate turbulence (HRT). The onset and slope of HRT have each been reported to be independent and powerful predictors of clinical prognosis in patients with myocardial infarction (MI), but there are no data available for patients with hypertrophic cardiomyopathy (HCM). Thus the present study an...

American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society Scientific Statement on Noninvasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death

“…A smaller number of studies of patients with nonischemic dilated cardiomyopathy, chronic congestive heart failure, or hypertrophic cardiomyopathy (HCM) and patients undergoing revascularization have also suggested a predictive value of heart rate turbulence. 24,149,[151][152][153][154] In the Marburg Cardiomyopathy Study of 242 patients with nonischemic dilated cardiomyopathy, 155 heart rate turbulence onset was a multivariate predictor of transplant-free survival (relative risk 2.95, 95% CI 1.11 to 7.48) but not of arrhythmic events.…”

Holter Monitoring and Long-Term Prognosis in Hypertrophic Cardiomyopathy

“…They were finally diagnosed as not having heart disease. Some of the control subjects and HCM patients in the present study had been enrolled in our previous studies [12,13] in which autonomic function was examined regarding the short-term prognosis in patients with HCM.…”

“…Analysis of heart rate turbulence was also performed on Holter recordings, as previously described [13,15]. We randomly selected three incidences of singular premature ventricular contraction preceded and followed by ≥20 normal sinus beats in each recording.…”

Evaluation of Arrhythmogenic Substrate in Patients With Hypertrophic Cardiomyopathy Using Wavelet Transform Analysis

“…9 However, they are localized and so small that we cannot detect them on the standard extracorporeal 12-lead ECG. Several approaches, such as spectro-temporal mapping, 19 spectral-turbulance analysis, 20 and heart rate variability 21,22 has been made to record them by surface ECG, but their utility is still uncertain.…”