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Although reduced heart rate (HR) variability during sinus rhythm is associated with an adverse prognosis in a variety of clinical settings, the significance of measures of variability of the ventricular response in atrial fibrillation (AF) requires clarification. AF is common among patients with chronic severe mitral regurgitation (MR) and potentially limits the application of HR variability techniques in this population. Therefore, this study examined the physiologic correlates and prognostic significance of measures of HR variability in 21 patients with nonischemic causes of chronic severe MR who had chronic AF and underwent 24-hour ambulatory electrocardiography as part of a prospective study of the natural history of regurgitant valvular heart disease. Patients were followed for up to 9.1 years and end points of mortality and progression to mitral valve surgery were tabulated. Time- and frequency-domain measurements of high, low-, and ultra-low-frequency HR variability were computed and compared with resting ventricular function by radionuclide cineangiography and outcome. All measures of HR variability were covaride (pairwise r values between 0.48 and 0.99, all p values [less than] 0.03), and none of the variables was significantly related to age, ventricular premature complex (VPC) density, or right or left ventricular ejection fraction. Reductions in time-domain measurements of ultra-low- and high-frequency HR variability were significant predictors of the combined risk of mortality or requirement for mitral valve surgery (p = 0.02 and p = 0.05, respectively). Thus, although measures of HR variability in AF with MR are not associated with age, VPC density, or ventricular performance, variability of the ventricular response in chronic AF is inversely related to risk in patients with chronic severe MR. (Am J Cardiol 1994;74:906-911)

Twenty-two late survivors of Mustard repair of transposition of the great arteries underwent treadmill exercise testing to assess exercise endurance, and radionuclide cineangiography to measure rest and exercise right ventricular (RV) and left ventricular (LV) ejection fraction (EF). Mean age at Mustard repair was 1.8 [+ or -] 2.4 years and at initial exercise study 14.1 [+ or -] 4.5 years. All patients were asymptomatic at study entry. Treadmill endurance time (9 to 12 minutes) was within the normal range for age in 18 of 20 patients. LVEF and RVEF at rest were within normal limits (55 [+ or -] 8% and 52 [+ or -] 9%, respectively). All LVEFs and RVEFs during exercise were also within the normal range (64 [+ or -] 8% and 57 [+ or -] 9%, respectively). However, the magnitude of increase in EF (rest to exercise) was subnormal for the right ventricle in 7 patients and for the left ventricle in 2 patients. Exercise RVEF was higher in patients with simple transposition who underwent repair at 1 year (62 [+ or -] 10% vs 52 [+ or -] 7%). Serial study in 6 patients revealed no change in average RVEF or LVEF after an average interval of 4.4 years. One patient with complex transposition subsequently developed refractory congestive heart failure requiring cardiac transplantation. It is concluded that exercise endurance and LVEF and RVEF at rest and exercise are generally well preserved up to 19 years after Mustard repair, particularly in cases of simple transposition of the great arteries repaired before 1 year of age. (Am J Cardiol 1994;74:478-482)

The natural history of patients with severe nonischemic mitral regulation (MR) from mitral valve prolapse, who are asymptometic or minimally symptomatic and have normal right ventricular (RV) and left vertricular (LV) performance, has not been evaluated previously. To define natural history in this population and to determine if any objective variables could predict disease progression, 31 patients were followed annually with severe MR due to prolapse, who at entry were asymptomatic or minimally symptomatic and had normal RV and LV performance at rest by radionuclide cineangiography. Average follow-up in patients not reaching surgical and point was 4.7 years. The Kaplan-Meier product limit estimates were used to determine the rate of progression to either 'operable' symptoms or to previously defined 'high risk' ventricular performance descriptors, if the after occurred first. Univariate comparisons of Kaplan-Meier curves and multivariate Cox proportional hazards analyses were used to define prognostically important variables measured at entry. Fourteen patients developed symptoms warranting referral for operation; none developed high-risk ventricular performance descriptors. The annual end point risk was 10.3%. Of all covariates, only change in RV ejection fraction from rest to exercise was significantly associated with disease progression. Annual risk of progression to surgical end point was 4.9% in the subgroup in which this parameter increased with exercise and 14.7% in the subgroup without an increase (p = 0.04). Patients with severe MR due to mitral valve prolapse, who are asymptomatic or minimally symptomatic with normal ventricular performance, can be expected to progress to surgical indications at an annual rate of 10.3%. The change in RV ejection fraction during exercise is useful in predicting the likelihood of such progression. (Am J Cardiol 1994;74:37

Anticardiolipin antibodies (acLa) are associated with a thrombotic tendency (often involving cerebral ischemic events), are frequently present with systemic lupus erythematosus and have been found together with cardiac valve abnormalities. Previous studies evaluated patients characterized by the presence of acLa or lupus, precluding assessment of the frequency of acLa in those with valvular disease. This study aims to establish the prevalence of acLa in patients with valve disease in the absence of lupus and, furthermore, to determine the influence of acLa on the risk of cerebral events in valve disease. Eighty-seven consecutive patients with mitral or aortic regurgitation, or both, prospectively underwent enzyme-linked immunosorbent assay testing for immunoglobulin G (IgG) and M acLa, as did 24 normal subjects. AcLa values [is greater than or equal to] 3 SD above the normal mean were considered 'positive.' Prior cerebral events were defined retrospectively. Of 87 patients with valvular disease, 26 had positive IgG acLa levels compared with 0 of 24 normal subjects (p

PURPOSE: To elucidate determinants of abnormal left ventricular functional responses to exercise in hypertensive patients. PATIENTS AND METHODS: One hundred twenty-seven patients with uncomplicated essential hypertension were studied by rest and exercise radionuclide angiography and by echocardiography at rest. RESULTS: The 24 patients with subnormal left ventricular ejection fraction at peak exercise (less than 54%) were similar in age and rest and exercise blood pressures to the 103 with normal exercise ejection fraction, but were more obese (p CONCLUSION: Among patients with uncomplicated essential hypertension, abnormal functional responses to exercise are strongly associated with eccentric ventricular hypertrophy, obesity, and high sodium intake., Hypertension (high blood pressure) increases the risk of congestive heart failure, the inability of the heart to pump blood, which results in congestion of the lungs. However, there are no methods to identify impaired function of the heart in hypertensive patients at a stage when the damage could be reversed. Studies have shown that a certain proportion of hypertensive patients have impaired heart functions during exercise. The factors contributing to impaired function of the left ventricle during exercise were assessed among 127 hypertensive patients. The patients were examined by angiography (X-ray of the blood vessels) both at rest and during exercise, and by echocardiography (the use of ultrasound waves to visualize heart structures) at rest. Twenty-four patients had less-than-normal left ventricular ejection fractions, the relative percentage of blood emptied from the left ventricle at the end of contraction, used as a measure of contractility. Although age and blood pressures at rest and during exercise were similar among all patients, patients with subnormal left ventricular ejection fraction tended to be obese. Impaired function of the left ventricle was associated with increases in size of the left ventricle; tension on the wall of the heart at the end of contraction; dietary sodium intake; and body weight. The results show that impaired function of the heart during exercise in hypertensive patients is associated with enlargement of the left ventricle, obesity, and high sodium intake. (Consumer Summary produced by Reliance Medical Information, Inc.)