CH.48

Calcium channels

Gated pores in the cytoplasmic membrane that regulate calcium entry into cells.

Vasoconstriction

The process by which calcium entry into blood vessels causes them to constrict.

Vasodilation

The effect caused by calcium channel blockade, leading to the widening of blood vessels.

AV conduction

The transmission of electrical impulses from the atria to the ventricles in the heart.

Myocardial contractility

The ability of heart muscle to contract; increased by calcium entry.

Calcium channel blockade

The action that decreases heart rate, AV conduction, and myocardial contractility.

Beta1-receptors

Receptors in the heart that, when activated, enhance calcium entry.

Dihydropyridines

A class of calcium channel blockers primarily affecting vascular smooth muscle (VSM).

Verapamil

A calcium channel blocker acting on both VSM and the heart, used for hypertension and dysrhythmias.

Diltiazem

A calcium channel blocker similar to verapamil, used for hypertension and dysrhythmias.

Angina pectoris

Chest pain caused by reduced blood flow to the heart, treated with calcium channel blockers.

Cardiac dysrhythmias

Irregular heartbeats that can be treated with verapamil and diltiazem.

Bradycardia

Slower than normal heart rate, a potential side effect of verapamil and diltiazem.

AV block

A condition where the electrical signal is delayed or blocked in the heart; can be caused by calcium channel blockers.

Reflex tachycardia

An increase in heart rate that can occur as a compensatory mechanism when blood vessels dilate.

Peripheral edema

Swelling in the ankles or feet, a side effect of calcium channel blockers.

Dizziness

A common side effect of calcium channel blockers resulting from vasodilation.

Constipation

A side effect particularly associated with verapamil that can be managed with dietary changes.

Toxicity

Adverse effects that may occur with high doses of calcium channel blockers.

Digoxin

A medication that can interact with verapamil and diltiazem, increasing risk of heart block.

Nifedipine

A dihydropyridine calcium channel blocker associated with reflex tachycardia and potential cardiovascular risks.

Immediate release (IR) formulations

Formulations of medications that can lead to more pronounced reflex tachycardia.

Sustained release (SR) formulations

Formulations designed to release medication slowly, associated with less reflex tachycardia.

Therapeutic goal of verapamil

Indicated for hypertension, angina pectoris, and cardiac dysrhythmias.

Therapeutic goal for dihydropyridines

Indicated mainly for essential hypertension and, in some cases, angina pectoris.

Grapefruit juice interaction

Can raise levels of verapamil and diltiazem, potentially leading to toxicity.

IV therapy with calcium channel blockers

Used primarily for treating cardiac dysrhythmias.

Baseline data for angina

Information on frequency and severity of anginal attacks before treatment.

High-risk patients for verapamil

Patients with severe hypotension, sick sinus syndrome, or significant AV block.

Cardiosuppression

Reduced cardiac function due to medications such as verapamil and diltiazem.

Cardiovascular monitoring

Observing ECG and vital signs during IV administration of calcium channel blockers.

Fluid and fiber intake

Dietary recommendations for patients taking verapamil to reduce constipation.

Plasma levels of digoxin

May be increased by the combination of digoxin with verapamil or diltiazem.

Dihydropyridine side effects

Includes peripheral edema and reflex tachycardia.

Monitoring blood pressure

A key practice to ensure effective treatment of hypertension with calcium channel blockers.

Essential hypertension

A common condition treated with calcium channel blockers.

Slow heartbeat

A manifestation of potential side effects from verapamil and diltiazem.

Weight gain

A symptom patients should monitor when using verapamil or diltiazem.

Manifestations of cardiac effects

Symptoms patients should be informed about, such as shortness of breath.

hemodynamic stability

A state desired during treatment of patients on calcium channel blockers.

IV administration specifics

Should be done slowly, over a period of 2 to 3 minutes to avoid adverse effects.

Monitoring for AV block

Important while administering IV calcium channel blockers.

Immediate cardioversion availability

Necessary when administering calcium channel blockers IV due to risk of dysrhythmias.

Patient education on symptoms

Essential for patients to understand signs of edema, constipations, or bradycardia.

Intravenous nicardipine

Administered for severe hypertension in acute settings.

Beta blocker interactions

Can enhance the cardiac suppression effects when given with verapamil or diltiazem.

Sign of edema to monitor

Swelling in the ankles or feet for patients on calcium channel blockers.

Patient compliance with administration

Instructing patients about proper intake of extended-release formulations of calcium channel blockers.