Increased production of nitric oxide in coronary arteries during congestive heart failure.

Experiments were designed to determine whether a heterogeneity of endothelium-dependent relaxations in arteries from different vascular beds exists in experimental congestive heart failure (CHF) and to determine the mediators of those responses. CHF was produced in dogs by rapid ventricular pacing for 15 d. Rings of coronary, femoral, and renal arteries with and without endothelium from control and CHF dogs were suspended in organ chambers for measurement of isometric force. In arteries contracted with prostaglandin F2 alpha, endothelium-dependent relaxations to BHT 920 (an alpha 2-adrenergic agonist) were increased in coronary arteries from dogs with CHF (maximal relaxation: control -15 +/- 9% vs CHF -92 +/- 5%; n = 5-6; P < 0.05), with a modest enhancement in renal arteries. Relaxations to adenosine diphosphate and the calcium ionophore were unchanged. Relaxations to BHT 920 in CHF were reduced by NG monomethyl-L-arginine (L-NMMA) and pertussis toxin but not by indomethacin. These data suggest that endothelium-dependent relaxations are affected heterogeneously in CHF. The enhanced response to alpha 2-adrenergic agonists in the coronary artery is mediated by nitric oxide through a mechanism sensitive to inhibition by pertussis toxin. This selective increase in endothelium-dependent relaxations in the coronary artery may contribute to preserving coronary blood flow during CHF.

Role of intraaortic balloon pump counterpulsation in high risk coronary rotational atherectomy.

OBJECTIVES: This study sought to evaluate the role of intraaortic balloon pump counterpulsation in preventing hemodynamic instability and promoting a successful outcome during percutaneous transluminal coronary rotational atherectomy in high risk patients. BACKGROUND: The application of rotational atherectomy has widened to include patients with complex lesions and left ventricular dysfunction. Although intraaortic balloon pumping has been successfully used to provide hemodynamic support during balloon angioplasty, its role in high risk rotational atherectomy has not yet been defined. METHODS: In a retrospective review of 159 consecutive high risk patients who underwent rotational atherectomy, 28 had an intraaortic balloon pump placed electively before the procedure (Group 1) whereas 131 did not (Group 2). RESULTS: Group 1 was older and more likely to have multivessel disease and left ventricular dysfunction. Augmented diastolic pressure was maintained > 90 mm Hg in all Group 1 patients, and significant procedure-related hypotension was encountered in nine Group 2 patients, requiring an emergency intraaortic balloon pump in five. Procedural success was achieved in all 28 patients in Group 1 and in 118 in Group 2 (p = 0.07). Slow flow occurred in 18% and 17% of Group 1 and 2 patients, respectively. Among patients with slow flow, non-Q wave myocardial infarction occurred only in Group 2 (0% vs. 27%). On multivariate analysis, elective intraaortic balloon pump placement was the only variable to correlate with a successful procedure uncomplicated by hypotension (p < 0.05). Hospital stay and vascular complications were similar in both groups. CONCLUSIONS: Elective placement of an intraaortic balloon pump before coronary rotational atherectomy in selected high risk patients promotes both procedural hemodynamic stability and a successful outcome.

Late outcome after percutaneous transluminal coronary angioplasty during acute myocardial infarction.

Early reperfusion for acute myocardial infarction (AMI) results in improved ventricular function and survival. There is a dearth of data on long-term survival (> 5 years) after percutaneous transluminal coronary angioplasty (PTCA) performed either as a primary procedure or in conjunction with thrombolytic therapy. We studied 160 patients who underwent PTCA during AMI between 1981 and 1987 either with (n = 101) or without (n = 59) streptokinase therapy. Mean time to reperfusion was 4.6 hours, and patency was achieved in 134 patients (84%). Mean discharge ejection fraction was 46 +/- 14%. Coronary artery bypass grafting was performed before dismissal in 34 patients (21%), including 21 of 130 patients (16%) with 1- or 2-vessel disease and 13 of 30 patients (43%) with 3-vessel disease (p < 0.05). Eleven patients (7%) died in the hospital. The 149 hospital survivors were followed for a mean of 69 +/- 21 months (median 72). During follow-up, 22 patients (15%) died, 21 (14%) had reinfarction, 23 (15%) underwent coronary artery bypass grafting, and 21 (14%) underwent repeat PTCA of the infarct-related artery. On univariate analysis, age > or = 62 years, multivessel disease, ejection fraction < or = 40%, previous AMI, and being a nonsmoker at the time of AMI were predictive of late mortality (p < 0.05 each variable). On multivariate analysis, only ejection fraction < or = 40% and prior AMI were predictive of late death. In patients treated with PTCA for AMI, late survival is excellent. Early surgical revascularization of high-risk patients may contribute to these encouraging results.

Endothelin: a new cardiovascular regulatory peptide.

Endothelin, a recently discovered peptide produced by endothelial cells, contracts vascular strips in vitro with greater potency than any previously known vasoconstrictor. Infusions of pharmacologic doses of endothelin in vivo result in a prolonged pressor response and a preferential impairment of renal hemodynamic and excretory functions. Endothelin also directly stimulates the release of aldosterone from the adrenal gland and inhibits renin release in vitro. A highly sensitive and specific radioimmunoassay has confirmed that endothelin circulates in human plasma, and increased plasma endothelin levels have been associated with various cardiovascular disease states. This review summarizes the current knowledge about the molecular biologic features and physiologic actions of endothelin and also explores the role of endothelin, through its local and systemic function, as a regulator of vascular tone in normal and pathophysiologic states.

Cardiac fibroma mimicking apical hypertrophic cardiomyopathy: a case report and differential diagnosis.

A 55-year-old man was seen with palpitations, dyspnea, syncope, and a large apical left ventricular mass. A diagnosis of apical hypertrophic cardiomyopathy had been made by cardiac catheterization 10 years previously. Transthoracic echocardiography performed during the current evaluation, however, was suggestive of a primary cardiac tumor. At operation, a large fibroma was excised. Knowledge of the echocardiographic appearance of apical left ventricular abnormalities can be helpful in determining the most appropriate choice of therapy.

Cardiac atrial natriuretic factor during evolution of congestive heart failure.

Congestive heart failure (CHF) is a pathophysiological condition associated with increased plasma levels of atrial natriuretic factor (ANF), a peptide hormone of cardiac origin that participates in the homeostatic control of intravascular volume and vascular tone. Atrial myocytes serve as the principal source of ANF under physiological conditions, although recent studies have demonstrated that ventricular myocardium may also synthesize ANF in models of CHF associated with ventricular hypertrophy. The current study was designed to investigate the roles of atrial and ventricular myocardium to synthesize, store, and release ANF during the evolution of tachycardia-induced CHF in the dog. The present study demonstrates a persistent elevation of plasma ANF during the evolution of CHF. In acute CHF (3 h), plasma ANF increased independent of cardiac ANF synthesis. In chronic CHF (15 and 30 days), plasma ANF is maintained by an increase in atrial synthesis and release of the peptide, without recruitment of ventricular ANF synthesis. The present study demonstrates that in acute CHF the increase in plasma ANF is regulated by release of stored peptide, and in chronic CHF the persistent elevation of plasma ANF is maintained by an increase in atrial synthesis of ANF.