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CARDIOLOGY. VALVULAR HEART DISEASE. Valvular Heart Disease Overview. The four heart valves function to force blood flow in the forward direction only as the ventricles contract. Valvular heart disease may be: Stenotic causing obstruction flow Incompetent allowing backward regurgitation
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CARDIOLOGY VALVULAR HEART DISEASE
Valvular Heart DiseaseOverview • The four heart valves function to force blood flow in the forward direction only as the ventricles contract. • Valvular heart disease may be: • Stenoticcausing obstruction flow • Incompetent allowing backward regurgitation • The disease process can be • Acute • Subacute • Chronic
Valvular Heart DiseaseAcute Adaptations • Tachycardia • Increased myocardial contractility • Arteriolar vasoconstriction • This is all in the attempt to maintain cardiac output and perfusion pressure to vital organs
Valvular Heart DiseaseSubacute Adaptations • Fluid retention producing an increase in venous volume and ventricular filling pressures • Attempts to maintain effective stroke volume by the Frank-Starling Principle
Valvular Heart DiseaseChronic Adaptations • Acute and Subacute adaptations • Ventricular hypertrophy/dilatation • Occurs when either the outflow valve or the inflow valve is stenotic or incompetent. • Atrial dilatation • Occurs when the atrioventricular valve is stenotic or incompetent • Chronic adaptations are able to preserve cardiac output and prevent pulmonary congestion for many years.
Valvular Heart DiseaseGeneral Therapy • Medical side effects only; systemic and pulmonary venous congestion • Surgical best treatment; main concern is when is the best time for surgical intervention in individual patients.
Mitral Stenosis • Usually the result of rheumatic heart disease. • Requires years of progressive damage to present with clinical manifestations. • Hemodynamic abnormality is an elevated diastolic pressure • Normal mitral valve areas is 4-6 cm squared • Increased diastolic pressure is found when orifice size is below 2.5 cm squared. • Pulmonary congestion occurs below 1.5 cm squared • Right heart failure below 1 cm squared
Mitral StenosisClinical Features • Most common early symptom is dyspnea. Precipitated by: • Exertion • Tachycardia • Anemia • Pregnancy • Infection • These patients need to have a slow heart rate and long diastole to keep left atrial pressure and pulmonary venous pressure as low as possible.
Mitral StenosisClinical Features • Patient eventually will develop paroxysmal nocturnal dyspnea and orthopnea • The enlarged and irritable left atrium commonly produces PAC’s, atrial fibrillation, and rarely atrial flutter. • Patients with mitral stenosis are susceptible to pulmonary infections because of sustained vascular congestion • Circulatory stasis may lead to deep venous thrombosis, pulmonary embolism and pulmonary infarction
Mitral StenosisClinical Features • Thrombi may form in the atria or on the valve leaflets, especially in patients in atrial fibrillation, and may embolize to arteries supplying the brain, kidneys, spleen or extremities
Mitral StenosisTreatment • Initially treat the acute complications • Surgical intervention is advised
Mitral Valve Prolapse • Due to a mismatch between the size of the left ventricular cavity and the mitral valve apparatus • Involves a portion of the posterior mitral valve leaflet (prolapses into left atrium) and occurs during mid to late systole. • Many patients experience symptoms, but most are asymptomatic.
Mitral Valve ProlapseClinical Features • Most patients are diagnosed on incidental findings during a routine physical examination. • Some have chest pain (tension on the papillary muscles) • Some have palpitations (atrial or ventricular tachyarrhythmias) • Syncope from tachyarrhythmias or orthostatic hypotension
Mitral Valve ProlapseComplications • Infective endocarditis • Thrombi forming on the leaflets and embolizing to the ophthalmic or cerebral circulation; presenting as TIA or stroke. • Sudden Death Ventricular fibrillation
Mitral Valve ProlapseCommon Arrhythmias • Sinus Arrhythmia • Premature atrial complexes • Premature ventricular complexes • Paroxysmal supraventricular tachycardia • Atrial fibrillation
Mitral Valve ProlapseTreatment • Chest pain and arrhythmias beta-adrenergic antagonists • Antibiotics
Valvular Aortic Stenosis • Usually develops from: • Rheumatic heart disease • Congenitally bicuspid aortic valve • Rheumatic inflammation of the leaflets causes fusion fibrosis calcification. Valve becomes both stenotic and incompetent. • Symptoms usually present at 40-60 years of age • The principal hemodynamic abnormality is obstruction to left ventricular outflow • Normal opening is 3-4 cm squared
Valvular Aortic StenosisClinical Features • Angina pectoris • Syncope • Left Heart Failure • Dyspnea • Pulmonary edema • Initially BP is normal, but as the disease progresses, systolic BP falls and pulse pressure narrows
Valvular Aortic StenosisTreatment • Strenuous physical exertion should be avoided • Antibiotics for bacterial endocarditis • CHF salt restriction, diuretics and digoxin • Nitrates for chest pain use cautiously because of hypotensive effects. • Prosthetic replacement of the valve for those that develop symptoms of angina, syncope or CHF
Tricuspid Stenosis • Uncommon valvular disease. Due to rheumatic heart disease. Associated with: • Tricuspid regurgitation • Mitral stenosis • Aortic stenosis
Tricuspid Stenosis • With rheumatic tricuspid stenosis, the symptoms are primarily due to: • Left heart failure • Pulmonary hypertension • Normal valve size is 7 cm squared. Significant obstruction occurs below 1.5 cm squared
Tricuspid StenosisClinical Features • Characterized by signs of increased systemic venous pressure: • Ascites: abnormal pooling of fluid in the abdominal cavity containing large amounts of protein and other cells. • Peripheral edema • Pulmonary congestion is absent and cardiac output is usually diminished • Jugular vein distention is present
Tricuspid StenosisTreatment • Relief of systemic venous congestion • May require valve replacement
Pulmonary Stenosis • Most common cause: • Congenital • Tetralogy of Fallot
Pulmonary StenosisTetralogy of Fallot • Made up of four heart defects: • Pulmonary stenosis (lung narrowing) • Ventricular septal defect • Malposition of the aorta so that it arises from the septal defect (receives blood from both ventricles) • Enlargement of the right ventricle • Referred to as “Blue Baby”
Pulmonary StenosisClinical Features • Dyspnea • Right heart failure • Syncope and sudden death occur • Jugular vein distention present
Pulmonary StenosisTreatment • Relief of symptoms of venous congestion • Valve replacement