tailieunhanh - Cardiology Core Curriculum A problem-based approach - Part 6

Điều này có thể đòi hỏi phải giảm liều thuốc lợi tiểu hoặc thậm chí là một "kỳ nghỉ thuốc lợi tiểu" cho 1 hoặc 2 ngày để giới thiệu các chất ức chế ACE. Một chuẩn độ trở lên chậm cũng sẽ làm tăng khả năng liều nhắm mục tiêu sẽ đạt được | Cardiology Core Curriculum at the flat portion of the Starling curve. This may require a reduction in the diuretic dose or even a diuretic holiday for 1 or 2 days in order to introduce ACE inhibitors. A slow upward titration will also increase the likelihood that targeted doses will be reached. Adverse reactions include the development of an ACE inhibitor-induced cough this is mediated by bradykinins which are increased with ACE inhibition. No specific therapy is effective in relieving cough. Patients either cope with antitussives or discontinue therapy. Less frequently development of angioneurotic edema drug eruptions and rarely drug-induced neutropenia occur. ACE inhibitors are contraindicated in pregnancy. Several points regarding ACE inhibitor therapy for heart failure should be remembered. ACE inhibitors are indicated in all patients with heart failure and left ventricular systolic dysfunction. Therapy should mimic that of the major survival trials in terms of dose and agent selected. ACE inhibitors should not be suspended or discontinued because of hypotension unless the patient is symptomatic. This is because of the interrelationship between blood pressure BP cardiac output CO and systemic vascular resistance SVR which is defined by BP CO X SVR. Even though ACE inhibitors and other vasodilators decrease SVR the corresponding increase in CO offsets any drop in BP unless the patient is volume depleted. Angiotensin II receptor antagonists These agents competitively inhibit the receptors for angiotensin II and there is a lack of associated cough because there is no effect on bradykinins. The weight of evidence suggests that these agents should be considered in patients being treated with digitalis diuretics and a P-blocker who cannot tolerate an ACE inhibitor because of cough or P-Blockers Activation of the sympathetic nervous system adversely influences the course of chronic heart failure. Until relatively recently it was thought that .