The pathophysiology of advanced heart failure

The natriuretic peptides: physiology and role in left-ventricular dysfunction

The natriuretic peptides (NPs), atrial natriuretic peptide, and brain natriuretic peptide (BNP) have been shown to have important roles in fluid volume homeostasis and blood pressure regulation. In addition, plasma NP levels are elevated in a number of cardiac pathologies and have been used as biochemical markers of left-ventricular dysfunction (LVD) in small- and large-scale clinical studies. In this review, the authors describe NP physiology and summarize the findings of selected studies that have examined the reliability and feasibility of NP measurement in LVD. In particular, BNP is proposed to be a biochemical marker that may provide a useful and inexpensive screening test of LVD. In addition, the authors discuss possible roles of the NPs in the etiology and progression of LVD. The findings of these studies suggest that the NPs may directly contribute to cardiac pathophysiology and LVD progression.

Endothelial dysfunction associated with left ventricular diastolic dysfunction in patients with coronary heart disease

OBJECTIVE

We sought to assess the correlation between endothelial vasodilation and left ventricular diastolic function.

BACKGROUND

Previous studies have demonstrated that similar neurohumoral factors are involved in myocardial and vascular endothelial impairment. The degree of endothelial dysfunction is related to the clinical severity of the heart failure. However, it is not clear whether endothelial dysfunction develops with the progression of left ventricular diastolic dysfunction. We hypothesize that the endothelial dysfunction is associated with left ventricular diastolic dysfunction.

METHODS

Using high-resolution ultrasound, we measured the dilator response of the brachial artery to hyperemia (endothelium-dependent vasodilation) and to 0.5 mg nitroglycerin (endothelium-independent vasodilation), and measured peak velocities of the early wave (Evmax) and the atrial wave (Avmax) in 40 coronary heart disease (CHD) patients and 20 normal subjects. We analyzed the relationship between the Evmax/Avmax ratio and endothelium-dependent vasodilation.

RESULTS

The results showed that endothelium-dependent and endothelium-independent vasodilation as well as the Evmax/Avmax ratio were lower in the CHD group than those in the control group (4.29%+/-1.42%, 17.58%+/-2.99%, 0.81+/-0.24 vs. 9.62%+/-2.34%, 24.18%+/-3.15%, 1.07+/-0.29, respectively, P<0.01). The Evmax/Avmax ratio was related to endothelium-dependent vasodilation (r=0.45, P<0.01).

CONCLUSIONS

Our results showed that the development of endothelial dysfunction was associated with the progression of myocardial diastolic dysfunction, which suggests that the same mechanisms may be involved in the impairment of endothelium and myocardium.

Combining nonpharmacologic therapies for advanced heart failure: the Münster experience with the assist device-defibrillator combination

Implantable cardioverter defibrillators (ICDs) and ventricular assist devices (VADs) have been used as a bridge to cardiac transplantation. In selected patients, the combined implantation may be required. This study was motivated by a case of a 33-year-old female patient with giant cell myocarditis who died of ventricular tachyarrhythmias after having been placed on a VAD with which she had been treated on an out-of-hospital basis for a prolonged period of time. A subsequent retrospective analysis of our data showed that, of 73 patients who had to be bridged mechanically (54 Novacor, 12 TCI Heartmate, 4 Thoratec, 3 Medos) in our institution between 1993 and 1998, 10 patients had undergone defibrillator implantation either before (n = 8) or after (n = 2) implantation of a VAD. The cases are presented, and the feasibility of the combination therapy discussed.