Related Experiment Video

Updated: Oct 21, 2026

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
18:11

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

Published on: December 28, 2012

Theoretical considerations in the use of calcium entry blockers in silent myocardial ischemia

M H Crawford1

  • 1University of Texas Health Science Center, Department of Medicine/Cardiology, San Antonio 78284-7872.

Circulation
|December 1, 1989
PubMed

Insights

Treating asymptomatic myocardial ischemia involves balancing oxygen supply and demand. Heart rate control is key, with calcium channel blockers showing promise for managing silent ischemia and reducing oxygen demand.

Area of Science:

  • Cardiology
  • Pharmacology

Background:

  • Asymptomatic myocardial ischemia arises from an imbalance in myocardial oxygen supply and demand.
  • Coronary vasomotor tone and heart rate increases are critical factors in silent ischemia development.

Purpose of the Study:

  • To review the efficacy of antianginal agents in treating asymptomatic myocardial ischemia.
  • To evaluate the role of heart rate control and side-effect profiles in therapy selection.

Main Methods:

  • Review of existing literature on antianginal agents (nitrates, beta-blockers, calcium entry blockers).
  • Analysis of comparative studies on monotherapy and combination therapies for silent ischemia.
  • Consideration of drug side-effect profiles and ideal therapeutic characteristics.

Main Results:

  • Nitrates, beta-blockers, and calcium entry blockers are effective monotherapies for silent ischemia.
  • Therapies controlling heart rate increases during activity are superior to those increasing average heart rate.
  • Calcium entry blockers (diltiazem, verapamil) most closely resemble an ideal therapy by reducing vasomotor tone and oxygen demand.

Conclusions:

  • Pharmacological therapy for asymptomatic myocardial ischemia requires careful consideration of efficacy, heart rate control, and side effects.
  • Calcium entry blockers offer a promising approach for managing silent ischemia.
  • Further research is needed to establish the prognostic benefit and risk-benefit ratio of treating asymptomatic myocardial ischemia.

More Related Videos

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents10:53

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents

Published on: July 3, 2013

Isolation of Human Ventricular Cardiomyocytes from Vibratome-Cut Myocardial Slices11:19

Isolation of Human Ventricular Cardiomyocytes from Vibratome-Cut Myocardial Slices

Published on: May 10, 2020

Related Concept Videos

Antihypertensive Drugs: Action of Calcium Channel Blockers01:18

Antihypertensive Drugs: Action of Calcium Channel Blockers

Calcium ions are essential to contract smooth muscle cells in blood vessels. They enter these cells through voltage-dependent calcium channels, specifically L-type calcium channels in the cell membrane. These L-type calcium channels are integral to the excitation-contraction coupling process in smooth muscle. When a stimulus is received by smooth muscle cells, their membrane depolarizes. This alteration in membrane potential instigates the opening of L-type calcium channels. As a result,...
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers01:22

Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers

Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart.
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of the heart's...
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers01:20

Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers

Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Ischemic Heart Disease: Overview01:17

Ischemic Heart Disease: Overview

Ischemic heart disease occurs when the heart's blood supply dwindles, causing an ominous lack of oxygen and nutrients. This deficiency, stemming from reduced or obstructed blood flow, spells danger, leading to heart muscle damage and dysfunction.
Atherosclerosis, the primary malefactor, orchestrates this dangerous condition. It manifests as the accumulation of fatty deposits, akin to insidious plaques, within arterial walls. As time elapses, these plaques metamorphose, hardening and narrowing...
Antianginal Drugs: Calcium Channel Blockers and Ranolazine01:25

Antianginal Drugs: Calcium Channel Blockers and Ranolazine

Angina pectoris, a primary symptom of ischemic heart disease, requires careful pharmacological interventions. In this context, calcium channel blockers (CCBs) and ranolazine have emerged as crucial pharmacotherapeutic agents, providing deep insights into the complexities of angina management.
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...