Angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists in the treatment of heart failure caused by left ventricular systolic dysfunction.

Activation of the renin-angiotensin-aldosterone system (RAAS) in left ventricular systolic dysfunction is a critically important determinant in the pathophysiologic processes that lead to progression of heart failure and sudden death. Angiotensin II, acting at the specific angiotensin receptor (AT1-R), activates a series of intracellular signaling sequences which are ultimately expressed within the cardiovascular system as vasoconstriction and associated vascular hypertrophy and remodeling. Angiotensin converting enzyme (ACE) inhibition leads to increases in the vasodilatory peptides bradykinin and substance P and at least an initial reduction in angiotensin II concentrations. AT1-R blocking drugs prevent access of angiotensin II to the AT1-R and thus prevent cellular activation. ACE inhibitors have clearly been demonstrated through a large number of clinical trials to increase survival in congestive heart failure, primarily by reducing the rate of progression of left ventricular dilatation and decompensation. However, this beneficial effect diminishes over time. Preliminary short-term clinical studies evaluating the efficacy of AT1-R blocking drugs in the treatment of heart failure have suggested that they elicit similar hemodynamic and neuroendocrine effects as do the ACE inhibitors. The combination ACE inhibitors and AT1-R blocking drugs offer the theoretical advantage of increasing bradykinin while blocking the actions of angiotensin II, and thus possibly show a synergistic effect. Again, preliminary studies have yielded encouraging results that are difficult to interpret because neither ACE inhibitor nor the AT1-R blocking drug doses were titrated to tolerance. Pharmacological manipulation of the RAAS has led to better understanding of its role in heart failure and improved clinical outcomes.

Modern evaluation of the hypertensive patient: autonomic tone in cardiovascular disease and the assessment of heart rate variability.

Analysis of heart rate variability (HRV) permits an assessment of sympathetic and parasympathetic activity from EKG recordings. Analysis of HRV may be performed in both the time and frequency domain by the application of mathematical principles of signal processing. HRV demonstrates abnormalities in myocardial infarction, sudden death, heart failure, autonomic neuropathy and hypertension. The technique is useful for assessing prognosis and for evaluating therapeutic interventions.

Long-term therapy for heart failure with continuous ambulatory peritoneal dialysis.

This article reports the treatment with continuous ambulatory peritoneal dialysis of a patient with intractable congestive heart failure secondary to an ischemic cardiomyopathy. Although the use of peritoneal dialysis to treat refractory heart failure is not new, the advent of an effective continuous peritoneal dialysis system has allowed its use over prolonged periods of time. The two-year treatment interval described herein represents the longest reported application of this technique, to the best of our knowledge.