Value of the electrocardiogram in determining cardiac events and mortality in myotonic dystrophy

Electrocardiograms were recorded at baseline and regular intervals in 53 patients with myotonic dystrophy who were followed for a mean of 6.3 +/- 4.0 years. Patients with cardiac events had a significantly prolonged PR interval (p <0.001), a later age of onset of neuromuscular symptoms (p <0.05), and were older (p <0.005).

Regional cardiac compression due to a large anaerobic bacterial empyema

Compression of the heart outside the pericardial sac is a rare cause of hemodynamic compromise and cardiac tamponade. We report an atypical case of regional cardiac compression caused by a large loculated anaerobic bacterial empyema.

Effects of regular exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension

BACKGROUND

The prevalence of hypertension and its cardiovascular complications is higher in African Americans than in whites. Interventions to control blood pressure in this population are particularly important. Regular exercise lowers blood pressure in patients with mild-to-moderate hypertension, but its effects in patients with severe hypertension have not been studied. We examined the effects of moderately intense exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension.

METHODS

We randomly assigned 46 men 35 to 76 years of age to exercise plus antihypertensive medication (23 men) or antihypertensive medication alone (23 men). A total of 18 men in the exercise group completed 16 weeks of exercise, and 14 completed 32 weeks of exercise, which was performed three times per week at 60 to 80 percent of the maximal heart rate.

RESULTS

After 16 weeks, mean (+/- SD) diastolic blood pressure had decreased from 88 +/- 7 to 83 +/- 8 mm Hg in the patients who exercised, whereas it had increased slightly, from 88 +/- 6 to 90 +/- 7 mm Hg, in those who did not exercise (P = 0.002). Diastolic blood pressure remained significantly lower after 32 weeks of exercise, even with substantial reductions in the dose of antihypertensive medication. In addition, the thickness of the interventricular septum (P = 0.03), the left ventricular mass (P = 0.02), and the mass index (P = 0.04) had decreased significantly after 16 weeks in the patients who exercised, whereas there was no significant change in the nonexercisers.

CONCLUSIONS

Regular exercise reduced blood pressure and left ventricular hypertrophy in African-American men with severe hypertension.

Subvalvular left ventricular outflow tract obstruction caused by "rhinonodular" calcification

Cardiac calcification is a common problem in patients with renal failure. Calcific deposits often affect the mitral annulus, the aortic valve, and the coronary arteries. We report an atypical case of cardiac calcification obstructing the left ventricular outflow tract with minimal aortic valve calcification.

Miles run per week and high-density lipoprotein cholesterol levels in healthy, middle-aged men. A dose-response relationship

OBJECTIVE

To examine the association between miles run per week and high-density lipoprotein cholesterol levels in healthy middle-aged men.

BACKGROUND

Regular exercise increases levels of high-density lipoprotein cholesterol. However, the exercise requirements for such increases are not well defined.

METHODS

Healthy, nonsmoking men (n = 2906; age, 43 +/- 4 years) completed a questionnaire on health habits and physical activities and a symptom-limited exercise test. They were then stratified on the basis of the number of miles run per week. Six groups, with mileages of 0, 5, 9, 12, 17, and 31 per week, were established.

RESULTS

A gradual increase in high-density lipoprotein cholesterol level was observed with increased miles (0.008-mmol/L [0.308-mg/dL] increase in high-density lipoprotein cholesterol level per mile). Most of the changes were associated with distances of 7 to 14 miles per week. Levels of low-density lipoprotein cholesterol, triglycerides, and the ratio of total cholesterol to high-density lipoprotein cholesterol also improved with weekly mileage. The high-density lipoprotein cholesterol level correlated significantly with all exercise components, anthropometric measures, and alcohol consumption. Group comparisons disclosed significant differences (P < .05) in exercise time to exhaustion, miles run per week, body fat, body weight, and body mass index. Age and alcohol consumption were similar across groups.

CONCLUSIONS

These results indicate a dose-response relationship between miles run per week, high-density lipoprotein cholesterol level, and other lipoprotein-lipid levels. Most changes were noted in those who ran 7 to 14 miles per week at mild to moderate intensities. A mile-age threshold for changes in high-density lipoprotein cholesterol level was not observed. However, when compared with those of the nonexercising group, high-density lipoprotein cholesterol levels attained statistical significance at 7 or more miles per week.