Time course of cardiac structural, functional and electrical changes in asymptomatic patients after myocardial infarction: their inter-relation and prognostic impact.

OBJECTIVES: We prospectively studied the relationship between left ventricular (LV) dilation, dysfunction, electrical instability and death in patients after a first myocardial infarction (MI) without symptoms of heart failure and ischemia. BACKGROUND: Mechanisms linking LV dysfunction and sudden death in patients after MI remained controversial. METHODS: Left ventricular volumes, hemodynamics, electrocardiogram and 24-h Holter recordings were sequentially obtained between two days and seven years after MI. Left ventricular catheterization and coronary angiography were performed, and revascularization was performed if appropriate. RESULTS: Death occurred in 16 (12%) of the 134 patients included; it was of cardiac origin in 14 (88%) and sudden in origin in 12 (75%) patients. Of 37 (28%) patients with LV dilation, 12 died (32%); four patients (5.8%) died in the group without dilation. Left ventricular dilation was closely related to signs of electrical instability, as indicated by a significant correlation between end-diastolic LV volume index, Lown score (r = 0.98, p < 0.0001) and QTc prolongation (r = 0.998, p < 0.01), respectively. CONCLUSIONS: Patients with progressive remodeling are at increased risk of sudden death in chronic MI. Cardiac electrical instability is closely related to progressive LV dilation. Parameters of electrical instability and remodeling are predictors of sudden death. The findings suggest that remodeling might serve as a link between dysfunction, electrical instability of the heart and sudden death after MI.

Impact of pharmacotherapy on lymphocyte volumes and activity of the Na+/H+ exchanger in patients with congestive heart failure.

Previous studies in patients with congestive heart failure (CHF) have revealed abnormalities of cellular volume that might have an impact on the dysregulation of peripheral vascular resistance. Human mononuclear leukocytes (HML) represent a model for the study of cellular volume regulation. We investigated the impact of enalapril and carvedilol on HML volume and on the activity of the Na+/H+ exchanger in 26 patients with CHF and 20 volunteers. Over a period of 4 weeks, 18 patients received enalapril in addition to the previous therapy while 8 patients additionally received carvedilol. HML diameters and the activity of the Na+/H+ exchanger were measured by a Coulter Counter. Both patient groups showed abnormally increased initial volumes of HML compared to the volunteer group at baseline. Four weeks of therapy with enalapril in addition to therapy with diuretics and digoxin did not result in a statistically significant reduction of lymphocyte volume, whereas add-on therapy with carvedilol to therapy with ACE inhibitors, diuretics and digoxin reduced the volume significantly. Alterations could not be found in the activity of the Na+/H+ exchanger in either patient group compared to volunteers. Supplementary drug therapy with carvedilol in patients with CHF leads to a reduction of the increased lymphocytic volume, possibly reflecting the beneficial effect of beta-blockade.

Sex-specific prenatal programming: a risk for fibromyalgia?

Women are four to eight times more likely to be affected by fibromyalgia syndrome (FMS). A lack of cortisol, potentially due to an adrenocortical deficit is postulated in FMS. The cause of such adrenal insufficiency is unknown. It could be assumed that stress exposure during critical periods contributes to vulnerability for FMS. These critical periods might include prenatal periods in which adversities may lead to an impaired development of the adrenal cortex, especially in females. More than 50% of FMS patients report major life events before the onset of the disease. Possibly due to adrenal insufficiency they may not be able to dampen their stress response by secreting sufficient glucocorticoids. Thus, stress mediators, such as catecholamines and pro-inflammatory cytokines, may be disinhibited and affect brain function. This might result in an enhanced responsiveness to external and internal pain- and fatigue-eliciting stimuli. In a study with female FMS patients (N= 93) those patients with a shorter gestational length (<38 weeks) showed a lower cortisol awakening response (CAR) than FMS subjects with a gestational length >38 weeks (F((3,31))= 2.94, P= 0.038). Additionally, more than 70% reported severe psychological stress alone or in combination with other factors at disease onset.

Progressive left ventricular dysfunction and remodeling after myocardial infarction. Potential mechanisms and early predictors.

BACKGROUND: Left ventricular enlargement and the development of chronic heart failure are potent predictors of survival in patients after myocardial infarction. Prospective studies relating progressive ventricular enlargement in individual patients to global and regional cardiac dysfunction and the onset of late chronic heart failure are not available. It was the aim of this study to define the relation between left ventricular dilatation and global and regional cardiac dysfunction and to identify early predictors of enlargement and chronic heart failure in patients after myocardial infarction. METHODS AND RESULTS: Left ventricular volumes, regional area shrinkage fraction in 18 predefined sectors (gated single photon emission computed tomography), global ejection fraction, and hemodynamics at rest and during exercise (supine bicycle, 50 W, 4 minutes, Swan-Ganz catheter) were assessed prospectively 4 days, 4 weeks, 6 months, and 1.5 and 3 years after first myocardial infarction. Seventy patients were assigned to groups with progressive, limited, or no dilatation. Patients without dilatation (n = 38) maintained normal volumes and hemodynamics until 3 years. With limited dilatation (n = 18), left ventricular volume increased up to 4 weeks after infarction and stabilized thereafter; depressed stroke volume was restored 4 weeks after infarction and then remained stable at rest. Wedge pressure during exercise, however, progressively increased. With progressive dilatation (n = 14), depressed cardiac and stroke indexes were also restored by 4 weeks but progressively deteriorated thereafter. Area shrinkage fraction as an estimate of regional left ventricular function in normokinetic sectors at 4 days gradually deteriorated during 3 years, but hypokinetic and dyskinetic sectors remained unchanged. Global ejection fraction fell after 1.5 years, whereas right atrial pressure, wedge pressure, and systemic vascular resistance increased. By multivariate analysis, ejection fraction and stroke index at 4 days, ventriculographic infarct size, infarct location, and Thrombolysis in Myocardial Infarction trial grade of infarct artery perfusion were significant predictors of progressive ventricular enlargement and chronic dysfunction. CONCLUSIONS: Almost 26% of patients may develop limited left ventricular dilatation within 4 weeks after first infarction, which helps to restore cardiac index and stroke index at rest and to preserve exercise performance and therefore remains compensatory. A somewhat smaller group (20%) develops progressive structural left ventricular dilatation, which is compensatory at first, then progresses to noncompensatory dilatation, and finally results in severe global left ventricular dysfunction. In these patients, depression of global ejection fraction probably results from impairment of function of initially normally contracting myocardium. Early predictors from multivariate analysis allow identification of patients at high risk for progressive left ventricular dilatation and chronic ventricular dysfunction within 4 weeks after acute infarction.