Left ventricular diastolic function during adrenergic stress in essential hypertension: acute and chronic effects of ACE inhibition

Deleterious Effects of Cold Air Inhalation on Coronary Physiological Indices in Patients With Obstructive Coronary Artery Disease

Background Cold air inhalation during exercise increases cardiac mortality, but the pathophysiology is unclear. During cold and exercise, dual-sensor intracoronary wires measured coronary microvascular resistance ( MVR ) and blood flow velocity ( CBF ), and cardiac magnetic resonance measured subendocardial perfusion. Methods and Results Forty-two patients (62±9 years) undergoing cardiac catheterization, 32 with obstructive coronary stenoses and 10 without, performed either (1) 5 minutes of cold air inhalation (5°F) or (2) two 5-minute supine-cycling periods: 1 at room temperature and 1 during cold air inhalation (5°F) (randomized order). We compared rest and peak stress MVR , CBF , and subendocardial perfusion measurements. In patients with unobstructed coronary arteries (n=10), cold air inhalation at rest decreased MVR by 6% ( P=0.41), increasing CBF by 20% ( P<0.01). However, in patients with obstructive stenoses (n=10), cold air inhalation at rest increased MVR by 17% ( P<0.01), reducing CBF by 3% ( P=0.85). Consequently, in patients with obstructive stenoses undergoing the cardiac magnetic resonance protocol (n=10), cold air inhalation reduced subendocardial perfusion ( P<0.05). Only patients with obstructive stenoses performed this protocol (n=12). Cycling at room temperature decreased MVR by 29% ( P<0.001) and increased CBF by 61% ( P<0.001). However, cold air inhalation during cycling blunted these adaptations in MVR ( P=0.12) and CBF ( P<0.05), an effect attributable to defective early diastolic CBF acceleration ( P<0.05) and associated with greater ST -segment depression ( P<0.05). Conclusions In patients with obstructive coronary stenoses, cold air inhalation causes deleterious changes in MVR and CBF . These diminish or abolish the normal adaptations during exertion that ordinarily match myocardial blood supply to demand.

Lisinopril. A review of its pharmacology and clinical efficacy in elderly patients

Lisinopril, the lysine analogue of enalaprilat, is a long-acting angiotensin converting enzyme (ACE) inhibitor which is administered once daily by mouth. The efficacy of lisinopril in reducing blood pressure is well established in younger populations, and many trials now show it to be effective in lowering blood pressure in elderly patients with hypertension. In comparative and non-comparative clinical trials, 68.2 to 89.1% of elderly patients responded (diastolic pressure < or = 90 mm Hg) to > or = 8 weeks' lisinopril treatment. Age-related differences in antihypertensive efficacy do not appear to be clinically significant, and dosages effective in elderly patients tend to range from 2.5 to 40 mg/day. Dosages usually need to be lower in patients with significant renal impairment. In congestive heart failure, lisinopril 2.5 to 20 mg/day increases exercise duration, improves left ventricular ejection fraction and has no significant effect on ventricular ectopic beats. It is similar in efficacy to enalapril and digoxin and similar or superior to captopril on most end-points. Data from the GISSI-3 post-myocardial infarction trial show that lisinopril reduced mortality and left ventricular dysfunction when given for 42 days starting within 24 hours of the onset of infarction symptoms. Results at 6 weeks and 6 months were similar in elderly and younger patients. Elderly patients, however, among other subgroups, exhibited a strong reduction in risk of low ejection fraction after treatment (-25.5%). Economic studies suggest that lisinopril is cost saving compared with other ACE inhibitors in some markets. When given according to the GISSI-3 protocol, lisinopril appears to be one of the less expensive of the successful ACE inhibitor regimens for acute myocardial infarction. In other trials, patients with diabetic nephropathy and hypertension improved or did not deteriorate during lisinopril treatment. Blood pressure was controlled and reductions or trends towards reductions in albuminuria were observed. These reductions were similar to those in diltiazem, nifedipine and verapamil recipients, and greater than those in patients receiving atenolol. Lisinopril appears to reduce mortality in diabetic patients after myocardial infarction and may also improve neuropathy associated with diabetes. Lisinopril is well tolerated and the profile of adverse events seen is typical of ACE inhibitors as a class. There is a tendency for more elderly than younger patients to discontinue treatment, but this trend is not clearly related to the incidence of adverse events in these age groups. Drug interactions occur with few other agents and are usually clinically significant only between lisinopril and either diuretics or lithium. Lisinopril is, thus, an effective treatment for elderly patients with hypertension, congestive heart failure and acute myocardial infarction and has shown promising benefits in patients with diabetic nephropathy.