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Data are analyzed from 5 patients who died suddenly during ambulatory electrocardiographic monitoring. Three of the patients were also assessed in terms of 2 recently developed indexes of heart rate (HR) variability. One of these, the standard deviation of RR intervals during successive 5-minute segments averaged over 24 hours, has been reported to be a(More)
Assessment of cardiac protein metabolism in thyroxine-induced left ventricular hypertrophy requires measurements of both protein synthesis and degradation. In vivo protein degradative rates can best be measured as the difference between rates of protein synthesis and growth. Accordingly, rates of left ventricular protein accumulation were determined in(More)
To determine the relative importance of protein degradation in the development of starvation-induced cardiac atrophy, in vivo fractional synthetic rates of total cardiac protein, myosin heavy chain, actin, light chain 1, and light chain 2 were measured in fed and fasted rabbits by continuous infusion of [3H] leucine. In addition, the rate of left(More)
We tested the hypothesis that transdermal scopolamine increases vagal-cardiac nervous outflow over the long term in 16 healthy young men. Twenty-four hours after application of one scopolamine patch, the average RR interval was increased by 13% and the average standard deviation of the RR interval (taken as an index of the level of vagal-cardiac nervous(More)
Standard electrocardiographic (ECG) criteria have exhibited poor correlation with left ventricular mass and poor sensitivity for left ventricular hypertrophy at acceptable levels of specificity. To assess the ability of the high-frequency filtered signal-averaged ECG to improve ECG correlation with left ventricular mass, signal-averaged orthogonal lead(More)
BACKGROUND The heart adapts to the volume overload of aortic regurgitation with dilation and hypertrophy. The development of left ventricular hypertrophy at the protein level is a dynamic process resulting from an imbalance between cardiac protein synthesis and degradation. The objective of the present study was to determine in vivo the relative(More)
Our results indicate the following. 1. HRV is markedly depressed in inducible SCD survivors, a group at high risk of a subsequent episode of SCD. 2. Studies on patients who developed SCD during Holter monitoring indicate that HRV is depressed prior to SCD. 3. HRV is markedly depressed in inducible "asymptomatic ventricular ectopy" patients, with the degree(More)
Aortic regurgitation was induced by retrograde perforation of an aortic valve cusp under hemodynamic guidance in 12 New Zealand White rabbits. Regurgitant fraction was documented by electromagnetic flow probe and six sham-operated animals served as controls. Two-dimensional, M-mode and Doppler echocardiography was performed pre-operatively and serially(More)
Previously reported experimental models of aortic regurgitation generally have manifested normal systolic performance and have not developed heart failure [Magid et al. Am. J. Physiol. 263 (Heart Circ. Physiol. 32): H226-H233, 1992]. To determine whether more severe chronic experimental aortic regurgitation would generate systolic malperformance, heart(More)