Comparative effects of doxazosin and hydrochlorothiazide on serum lipids and blood pressure in essential hypertension.

The efficacy and safety of doxazosin (mean dosage 6.9 mg, range 1 to 16) in the treatment of essential hypertension were compared in a double-blind study with those of hydrochlorothiazide (HCTZ) (mean dosage, 84.6 mg, range 25 to 100) in 104 hypertensive patients treated once daily for 6 months. Thirty-five patients were also assessed for comparative effects of the 2 agents on serum lipid parameters. Doxazosin produced potentially favorable changes from baseline in the concentrations of serum lipid fractions (total triglycerides, total cholesterol, high density lipoprotein [HDL] cholesterol and the derived HDL/total cholesterol ratio) compared with HCTZ. The decreases in total triglyceride and total cholesterol concentrations and an increase in the HDL/total cholesterol ratio were significantly different (p less than 0.006) from the opposite changes observed with HCTZ. Clinically relevant decreases from baseline in supine and standing blood pressures at 24 hours after administration did not significantly differ between the 2 agents. The incidence and severity of side effects were similar for both drugs. Three patients receiving doxazosin and 6 receiving HCTZ were withdrawn due to drug-related clinical side effects including 2 patients receiving HCTZ who were withdrawn because of laboratory test abnormalities. Eight HCTZ- and 1 doxazosin-treated patients developed hypokalemia and 6 HCTZ-treated patients developed hyperuricemia. These findings indicate that doxazosin and HCTZ provide comparable antihypertensive efficacy after 6 months of treatment using a once-daily regimen, but doxazosin produces a beneficial effect on the serum lipid profile as well as fewer biochemical aberrations.

Pathophysiology of chest pain in patients with cardiomyopathies and normal coronary arteries.

To clarify the pathogenesis of chest pain in patients with cardiomyopathies, we compared coronary blood flow and other indicators of ischemia at rest and during pacing-induced tachycardia in nine patients with cardiomyopathy (four hypertrophic and five congestive) and in five control subjects. Coronary blood flow was reduced at rest and during pacing in cardiomyopathy patients compared with controls. In patients with hypertrophic cardiomyopathy, pacing induced chest pain in all, increased ST-segment depression in three patients and increased coronary venous lactate concentration. With pacing, two of five patients with congestive cardiomyopathy had chest discomfort and three had increased ST-segment depression, but coronary venous lactate concentration did not change significantly. In both groups of cardiomyopathies, the ratio of the systolic and diastolic pressure-time indexes tended to decrease more than in controls during pacing. Thus, myocardial perfusion is decreased in patients with cardiomyopathy, both at rest and during pacing. The changes detected during pacing point to subendocardial ischemia as the likely mechanism for angina in hypertrophic and possibly also in congestive cardiomyopathy.

[Myocardial perfusion in myocardiopathies: study at rest and during induced tachycardia]. / La perfusion myocardique dans les cardiomyopathies. Etude au repos et lors de tachycardie induite.

The authors have compared myocardial perfusion, i.e. the coronary blood flow per unit of myocardial mass, in 9 patients with cardiomyopathy and 5 normal subjects, both at rest and during coronary sinus pacing-induced tachycardia at a rate of 150 beats/mn. In the cardiomyopathies, myocardial perfusion was found to be decreased at rest, and to remain abnormally low during induced tachycardia despite the evidence for a significant coronary reserve. During pacing there were, in addition to induced chest pain, indirect signs of sub-endocardial ischaemia which could explain the angina of effort found in certain cardiomyopathies, especially those of the obstructive hypertrophic type.