Ch. 19 - Heart Failure and Dysrhythmias

These flashcards cover key concepts, symptoms, types, and mechanisms related to heart failure and dysrhythmias based on the lecture notes.

Heart Failure

A general term used to describe several types of cardiac dysfunction that result in inadequate perfusion of tissues.

Symptoms of Left Heart Failure

Fatigue, weakness, shortness of breath, pulmonary congestion, paroxysmal nocturnal dyspnea.

Preload

Blood pressure in the left ventricle after filling and before the ventricles contract; derived from the venous system.

Afterload

Blood pressure in the systemic circulation that the heart must work against, created by the arteries.

Compensatory Mechanisms

Responses by the body to restore cardiac output towards normal, but may be harmful in the long term.

Dysrhythmias

Disturbances of the heart rhythm, ranging from missed beats to severe disturbances affecting the heart's pumping ability.

Types of Dysrhythmias

1. Abnormal rates of sinus rhythm, 2. Abnormal sites of impulse initiation, 3. Disturbances in conduction pathways.

Right-Sided Heart Failure

Characterized by increased systemic venous pressure resulting in edema and ascites, primarily due to congestion.

Left-Sided Heart Failure

Results in pulmonary congestion and decreased cardiac output, often leading to right-sided heart failure.

Biventricular Heart Failure

Progression of left-sided heart failure to right-sided heart failure, resulting in both pulmonary and systemic congestion.

Most Common Causes of HF

Myocardial ischemia, hypertension, dilated cardiomyopathy.

Systolic vs Diastolic HF

Systolic = ↓ contractility, ↓ EF.
Diastolic = impaired filling, normal EF.

Backward vs Forward Effects

Backward = congestion (pulmonary or systemic).
Forward = ↓ cardiac output (fatigue, confusion).

BNP Test

Elevated BNP helps diagnose heart failure.

Sympathetic Activation (HF)

↑ HR, ↑ contractility, ↑ vasoconstriction → short-term help, long-term harm.

RAAS Activation (HF)

Low CO → kidneys retain fluid → ↑ preload and congestion.

Myocardial Hypertrophy

Chronic high wall tension + neurohormones → ventricular remodeling.

HF Diagnosis

Symptoms, chest x-ray, echocardiogram, BNP.

HF Treatment Goals

↑ cardiac output and ↓ congestion/workload.

HF Medications

Diuretics (↓ preload), ACE inhibitors (↓ afterload), beta-blockers, digoxin (↑ contractility).

Pacemaker Therapy (HF)

Used to improve ventricular synchrony in wide QRS.

Sinus Tachycardia

100 bpm; due to SNS activation or low CO.

Sinus Bradycardia

<60 bpm; treat only if causing low CO.

Atrial Flutter/Fibrillation Key Risk

↑ stroke risk → requires anticoagulation.

Premature Ventricular Complexes (PVCs)

Wide QRS; frequent PVCs may reduce CO.

Ventricular Tachycardia

Wide, fast rhythm; life-threatening → needs rapid treatment.

Ventricular Fibrillation

No coordinated rhythm → fatal without CPR + defibrillation.