What is ventricular heart disease, including its types, etiologies, clinical presentation, diagnostic evaluation, and management recommendations, as described in Harrison's Principles of Internal Medicine?

Ventricular Heart Disease: Comprehensive Overview

Definition and Classification

Ventricular heart disease encompasses disorders affecting the ventricles that impair their ability to fill with or eject blood, leading to mechanical or electrical dysfunction. 1 This includes both structural abnormalities and functional impairments that result in heart failure, arrhythmias, or sudden cardiac death. 1

Primary Categories

Left Ventricular Disease:

• Systolic dysfunction with reduced ejection fraction (HFrEF), where coronary artery disease accounts for approximately two-thirds of cases 2, 3
• Diastolic dysfunction with preserved ejection fraction (HFpEF), affecting 20-40% of heart failure patients, predominantly elderly women with hypertension 3
• Cardiomyopathies including dilated, hypertrophic, restrictive, and infiltrative diseases 1

Right Ventricular Disease:

• Secondary to left heart disease, representing the most common form of pulmonary hypertension (65-80% of cases) 4
• Arrhythmogenic right ventricular cardiomyopathy (ARVC), with prevalence of 1:2,000 to 5,000 1
• Acute RV failure from pulmonary embolism, ARDS, or RV infarction 5

Etiologies

Left Ventricular Disease

• Ischemic heart disease: 40% of global heart failure cases and two-thirds of systolic dysfunction 2, 3
• Hypertension: Primary driver of diastolic dysfunction and HFpEF 3
• Valvular heart disease: Aortic stenosis, mitral regurgitation, mitral valve prolapse 1
• Cardiomyopathies: Dilated (1:250-500 prevalence), hypertrophic (1:250-500), restrictive 1
• Toxins and medications: Alcohol, chemotherapy agents, cocaine, amphetamines 1
• Myocarditis and inflammatory diseases 1

Right Ventricular Disease

• Left heart disease: Most common cause of RV dysfunction 4, 6
• Pulmonary hypertension: Both primary and secondary forms 4
• Coronary disease: RV infarction 5
• Congenital heart disease 1

Clinical Presentation

Symptoms of Left Ventricular Failure

Cardinal manifestations include dyspnea and fatigue limiting exercise tolerance, plus fluid retention causing pulmonary congestion and peripheral edema. 1, 3

• Dyspnea: Initially with exertion, progressing to rest in advanced disease 3
• Orthopnea and paroxysmal nocturnal dyspnea: Reflecting elevated left ventricular filling pressures 3
• Fatigue and reduced exercise capacity: Severely limiting functional status and quality of life 3
• Chest pain: May indicate underlying ischemia or pericardial involvement 1
• Palpitations, lightheadedness, syncope: Suggesting ventricular arrhythmias 1

Symptoms of Right Ventricular Failure

• Jugular venous distention with elevated jugular venous pressure 6
• Peripheral edema: Ankle swelling progressing to generalized edema 6
• Congestive hepatomegaly and ascites in advanced cases 6
• Dyspnea and exercise intolerance from impaired cardiac output 5

NYHA Functional Classification

• Class I: Symptoms only with efforts limiting normal individuals 3
• Class II: Symptoms with ordinary effort 3
• Class III: Symptoms with less than ordinary effort 3
• Class IV: Symptoms at rest 3

Diagnostic Evaluation

History and Physical Examination

Critical historical elements to elicit:

• Symptom characteristics: Palpitations, lightheadedness, syncope, dyspnea at rest or exertion, orthopnea, paroxysmal nocturnal dyspnea, chest pain, edema 1
• Precipitating factors: Exercise, emotional stress 1
• Known cardiac disease: Coronary, valvular (mitral valve prolapse), congenital 1
• Risk factors: Hypertension, diabetes, hyperlipidemia, smoking 1
• Medications: Antiarrhythmics, QT-prolonging drugs, stimulants including cocaine and amphetamines 1
• Past medical history: Thyroid disease, kidney disease, electrolyte abnormalities, stroke, epilepsy (arrhythmic syncope misdiagnosed as epilepsy), alcohol or illicit drug use 1
• Family history: Sudden cardiac death, sudden cardiac arrest, unexplained drowning in first-degree relatives; SIDS; cardiomyopathy; cardiac channelopathies (long QT, Brugada, short QT, CPVT); neuromuscular disease 1

Physical examination findings:

• Vital signs: Heart rate irregularity, blood pressure, effective bradycardia from bigeminy/trigeminy with apical-radial pulse deficit 1
• Jugular venous pressure elevation 1, 6
• Cardiac auscultation: Murmurs (aortic stenosis, mitral regurgitation), midsystolic click (mitral valve prolapse), gallops, rales 1
• Vascular examination: Carotid bruits, diminished peripheral pulses indicating atherosclerotic disease 1
• Peripheral edema 1, 6
• Sternotomy scars 1

Initial Diagnostic Testing

Transthoracic echocardiography is the diagnostic standard and must be obtained in all patients with known or suspected ventricular heart disease. 1, 2, 7

Echocardiographic assessment includes:

• Left ventricular ejection fraction, chamber size, ventricular mass 2, 8
• Wall motion abnormalities suggesting ischemia or infarction 7
• Valvular abnormalities and severity 1, 2
• Diastolic filling patterns providing prognostic information 8
• Right ventricular size and function 1, 4
• Pulmonary systolic pressure estimation 1, 4
• Functional mitral regurgitation as marker of adverse prognosis 8

Laboratory evaluation:

• Complete blood count, urinalysis, fasting lipid profile 2
• Liver function tests, serum electrolytes, blood urea nitrogen, serum creatinine 2
• Fasting glucose, thyroid-stimulating hormone 2
• BNP or NT-proBNP when clinical uncertainty exists, with high negative predictive value for ruling out heart failure 2

Electrocardiogram:

• Identify arrhythmias, conduction abnormalities, bundle-branch block, ventricular hypertrophy 1
• Q waves indicating ischemic disease or infiltrative cardiomyopathy 1
• QT interval assessment for channelopathies and torsades de pointes risk 1

Chest radiograph:

• Assess pulmonary congestion and lung pathology 1

Advanced Diagnostic Testing

Exercise testing is recommended in patients with:

• Intermediate or greater probability of coronary disease to provoke ischemic changes or ventricular arrhythmias 1
• Known or suspected exercise-induced ventricular arrhythmias including catecholaminergic VT 1
• Evaluation of response to medical or ablation therapy 1

Cardiac catheterization when:

• Noninvasive testing yields inconclusive data 1
• Discrepancy exists between noninvasive tests and clinical findings 1
• Direct intracardiac pressure measurements and cardiac output determination needed 1

Alternative imaging modalities:

• Cardiac MRI or CT when echocardiography is inadequate or additional tissue characterization needed 1, 2
• TEE for detailed valvular assessment or when transthoracic windows are poor 1
• PET imaging for viability assessment or specific infiltrative diseases 1

Risk stratification tools:

• T-wave alternans for improving diagnosis and risk stratification of life-threatening ventricular arrhythmias 1
• Signal-averaged ECG, heart rate variability, baroflex sensitivity, heart rate turbulence may be useful 1

Serial Monitoring

Repeat echocardiography is indicated when:

• Change in clinical status occurs 2
• Patient experiences or recovers from a clinical event 2
• Treatment that might significantly affect cardiac function has been administered 2
• Every 1-2 years if PVC burden is high to monitor for left ventricular dysfunction 7

Serial laboratory monitoring:

• Renal function and serum electrolytes to guide diuretic therapy and detect medication complications 2

Management Recommendations

Left Ventricular Systolic Dysfunction (HFrEF)

Guideline-directed medical therapy forms the foundation:

• ACE inhibitors or ARBs as first-line agents 3
• Beta-blockers to improve survival and reduce hospitalizations 3
• Diuretics for congestion management with careful monitoring 3
• Device therapy (ICD, CRT) based on LVEF and QRS duration per established guidelines 1

Left Ventricular Diastolic Dysfunction (HFpEF)

Blood pressure control is paramount, with aggressive management crucial. 3

• ACE inhibitors or ARBs as first-line agents to improve ventricular relaxation and promote regression of left ventricular hypertrophy 3
• Beta-blockers to control heart rate and increase diastolic filling time 3
• Diuretics used judiciously to reduce congestion and elevated filling pressures, with careful monitoring to avoid hypotension 3

Ventricular Arrhythmias

Management depends on presence of structural heart disease and symptom burden:

In structurally normal hearts:

• Asymptomatic PVCs carry excellent prognosis and do not require antiarrhythmic therapy 7
• Beta-blockers or non-dihydropyridine calcium channel blockers if symptoms develop 7
• Avoid Class IC antiarrhythmic agents without first excluding coronary artery disease and structural heart disease 7

In structural heart disease:

• Guideline-directed heart failure therapy and device implantation are critical 9
• Catheter ablation increasingly considered first-line alternative to medical therapy, particularly if PVC burden exceeds 15-20% or PVC-induced cardiomyopathy develops 7, 9
• Antiarrhythmic drugs when ablation not feasible, though limited by toxicity 9

Right Ventricular Failure

Identify and treat underlying cause as primary management strategy:

• Acute pulmonary embolism, ARDS, acute decompensation of chronic pulmonary hypertension, RV infarction, arrhythmia 5
• Judicious fluid management avoiding excessive preload 5
• Inotropes and vasopressors for hemodynamic support 5
• Mechanical ventilation with RV-protective strategy if required 5
• Assist devices in refractory cases 5

Critical Pitfalls to Avoid

Do not dismiss heart failure based solely on absence of peripheral edema or pulmonary rales, as these signs may be absent in early stages or well-treated patients. 2

Do not treat asymptomatic PVCs with antiarrhythmic drugs in patients without structural heart disease, as risks outweigh benefits. 7

Do not overlook family history of sudden cardiac death, cardiomyopathy, or channelopathies, as these significantly alter risk stratification and management. 1

Do not ignore medications causing QT prolongation (www.crediblemeds.org) or inducing Brugada pattern (www.brugadadrugs.org). 1

Do not underestimate effective bradycardia from bigeminy/trigeminy, which can result in inaccurate heart rate estimation and hemodynamic compromise. 1

Always identify the underlying cause of heart failure, as specific etiologies require targeted treatments beyond standard heart failure management. 2