Valvular Heart Diseases

Stenosis and Regurgitation

What are the two broad opposing pathophysiologic classifications of valvular heart disease?

Narrowing

What is the physical meaning of stenosis in a heart valve?

Leaking

What is the physical meaning of regurgitation in a heart valve?

Pressure Overload

What is the primary mechanical load exerted on a chamber by a stenotic valve?

Volume Overload

What is the primary mechanical load exerted on a chamber by a regurgitant valve?

Concentric Hypertrophy

What type of chamber remodeling features thickening of walls with a normal or smaller cavity size?

Eccentric Hypertrophy

What type of chamber remodeling features chamber dilation with proportional wall thickening?

Laplace's Law

Which physiological law governs cardiac remodeling and defines wall stress?

S = P x r / (2h)

What is the mathematical equation for Laplace's Law defining wall stress?

Wall stress

What does the variable S represent in the Laplace's Law equation?

Intraventricular pressure

What does the variable P represent in the Laplace's Law equation?

Chamber radius

What does the variable r represent in the Laplace's Law equation?

Wall thickness

What does the variable h represent in the Laplace's Law equation?

Increase wall thickness

What is the only mechanical mechanism available for the heart to decrease its wall stress according to Laplace's Law?

Concentric hypertrophy

What specific type of hypertrophy is prompted by the high pressure seen in valvular stenosis?

Eccentric hypertrophy

What specific type of hypertrophy is prompted by the increased radius seen in volume overload from regurgitation?

Chamber before the stenotic valve

Where does pressure build up significantly in valvular stenosis to push blood through the narrowed orifice?

Upstream and receiving chambers

Which chambers are affected by the backward leakage of blood in valvular regurgitation?

Rheumatic Heart Disease

What is the dominant cause of acquired valvular heart disease in the Philippines?

53.7 to 65.0 percent

What percentage of acquired valvular heart disease admissions in the Philippines are caused by Rheumatic Heart Disease?

53.7 percent

In what percentage of Rheumatic Heart Disease cases in the Philippines is the mitral valve involved?

Degenerative or Calcific VHD

What wear-and-tear valvular process is typically seen in elderly patients aged 60 and older?

20.0 to 25.0 percent

What percentage of acquired valvular heart disease cases in the Philippines are represented by degenerative or calcific etiology?

Infective Endocarditis

What condition causes 8.0 to 12.0 percent of acute valvular heart disease cases in the Philippines?

22 to 35 percent

What percentage of Infective Endocarditis cases in the Philippines occur on pre-existing Rheumatic Heart Disease valves?

Congenital Anomalies

What class of valvular etiology represents 5.0 to 8.0 percent of cases?

Bicuspid aortic valves

What is the most common congenital anomaly causing valvular heart disease?

Degenerative or Calcific AS

Which aortic stenosis phenotype is typically seen in patients over 70 years old and is characterized by wear-and-tear calcification?

Active bone building

What active cellular process drives degenerative calcific aortic stenosis rather than passive wear?

Osteoblast differentiation and inflammatory cascades

What two cellular processes drive the active bone building in degenerative calcific aortic stenosis?

ASCVD

The risk factors for calcific degenerative aortic stenosis match the risk factors of which other major disease?

Congenital Bicuspid Aortic Valve

Which aortic stenosis phenotype typically presents between ages 40 and 60 and is the most common congenital heart defect?

0.5 to 1.4 percent

What is the prevalence of congenital bicuspid aortic valves in the general population?

Accelerated wear and shear forces

What forces cause early stenosis and calcification in a congenital bicuspid aortic valve?

Ascending aortic aneurysms

Congenital bicuspid aortic valves are strongly associated with what vascular complication?

Medial degeneration

What pathological change in the aorta explains the association between bicuspid aortic valves and ascending aortic aneurysms?

Rheumatic AS

Which aortic stenosis phenotype typically presents between ages 20 and 40 and is dominant globally?

Commissural fusion and leaflet thickening

What are two structural features of Rheumatic Aortic Stenosis?

Mitral valve involvement and aortic regurgitation

Rheumatic aortic stenosis almost always co-exists with what other valvular involvements?

Left Ventricular Outflow Tract obstruction

What primary hemodynamic obstruction is caused by aortic stenosis?

LVP is much greater than AP

What systolic pressure relationship is created between the left ventricle and the aorta in aortic stenosis?

Concentric LVH

What structural left ventricular adaptation develops in response to the massive systolic pressure gradient in aortic stenosis?

Diastolic dysfunction

What functional ventricular impairment occurs because the thick left ventricular wall becomes stiff in aortic stenosis?

Elevated LVEDP

What filling pressure parameter is elevated as a result of left ventricular diastolic stiffness in aortic stenosis?

Pulmonary capillary wedge pressure

What pulmonary vascular pressure is raised when elevated LVEDP backs up into the left atrium and pulmonary capillaries?

Dyspnea

What primary respiratory symptom is caused by elevated pulmonary capillary wedge pressure in aortic stenosis?

Syncope, Angina, and Dyspnea

What are the three components of the classic aortic stenosis clinical triad?

Precipitously drops

What happens to a patient's prognosis once symptoms of the classic triad develop in untreated aortic stenosis?

Syncope

Which triad symptom is caused by a fixed cardiac output that cannot meet demand during exercise-induced vasodilation?

3 years

What is the average survival in years once syncope develops in untreated aortic stenosis?

Treadmill stress tests

What diagnostic evaluation is strictly contraindicated in symptomatic patients with severe aortic stenosis?

Angina

Which triad symptom is caused by a myocardial oxygen supply-demand mismatch in aortic stenosis?

3 years

What is the average survival in years once angina develops in untreated aortic stenosis?

Reduced aortic diastolic pressure

What vascular parameter drops and reduces coronary perfusion pressure in aortic stenosis?

Dyspnea or Heart Failure

Which triad symptom results from diastolic stiffness and elevated pulmonary capillary pressures?

2 years

What is the average survival in years once dyspnea or heart failure symptoms develop in untreated aortic stenosis?

Resting heart failure

What clinical state is highly lethal once a patient reaches the final stage of the aortic stenosis prognosis triad?

Crescendo-Decrescendo Murmur

What is the classic systolic murmur of aortic stenosis?

Right second intercostal space

Where is the crescendo-decrescendo murmur of aortic stenosis best heard?

Carotids

To which anatomical structures does the crescendo-decrescendo murmur of aortic stenosis radiate?

Late-peaking murmur

What feature of the crescendo-decrescendo murmur peaks later in the cardiac cycle as aortic stenosis severity increases?

Gallavardin Phenomenon

What clinical phenomenon is defined by the high-frequency musical component of the aortic stenosis murmur radiating to the apex?

Mitral regurgitation

The Gallavardin phenomenon mimics which other systolic murmur?

Pulsus Parvus et Tardus

What classic delayed and weak carotid pulse peak is heard in aortic stenosis?

Tardus

Which specific term describes the delayed peak of the carotid pulse in pulsus parvus et tardus?

Parvus

Which specific term describes the weak, small amplitude of the carotid pulse in pulsus parvus et tardus?

Soft or absent S2

What heart sound finding reflects heavily calcified, immobile aortic leaflets that fail to close?

Aortic closure component A2

What specific heart sound component is abolished in patients with a soft or absent S2 due to severe aortic stenosis?

S4 Gallop

What extra heart sound is heard in aortic stenosis, reflecting forceful atrial contraction into a stiff, hypertrophied left ventricle?

Fixed mechanical valvular obstruction

What is the underlying pathophysiology of aortic stenosis compared to HOCM?

Dynamic subvalvular obstruction by hypertrophied septum

What is the underlying pathophysiology of HOCM compared to aortic stenosis?

No effect on valve orifice

What effect does a smaller left ventricular cavity size have on the valve orifice in aortic stenosis?

Murmur gets softer

What happens to the murmur of aortic stenosis when left ventricular cavity volume decreases and flow drops?

Increases subvalvular obstruction

What effect does a smaller left ventricular cavity size have on subvalvular obstruction in HOCM?

Murmur gets louder

What happens to the murmur of HOCM when left ventricular cavity volume decreases?

Preload decreases and flow decreases

What are the two hemodynamic effects of the Valsalva maneuver or standing on the left ventricle in aortic stenosis?

Softer murmur

What happens to the aortic stenosis murmur during a Valsalva maneuver or standing?

LV cavity size decreases and obstruction increases

What are the two hemodynamic effects of the Valsalva maneuver or standing in HOCM?

Louder murmur

What happens to the HOCM murmur during a Valsalva maneuver or standing?

Preload increases and flow increases

What are the two hemodynamic effects of squatting or a passive leg raise in aortic stenosis?

Louder murmur

What happens to the aortic stenosis murmur during squatting or a leg raise?

LV cavity size increases and obstruction decreases

What are the two hemodynamic effects of squatting or a passive leg raise in HOCM?

Softer murmur

What happens to the HOCM murmur during squatting or a leg raise?

Avoid dehydration, diuretics, and nitrates

What is the primary medical goal or precaution when managing a patient with severe aortic stenosis?

LVEDP-dependent

Why must diuretics and nitrates be avoided in patients with severe aortic stenosis?

Maintain fluids and beta-blockers

What is the primary medical goal to keep the left ventricular cavity large in patients with HOCM?

Primary leaflet problem or secondary aortic root abnormality

What are the two primary anatomic categories that cause aortic regurgitation?

Rheumatic disease, BBAV, Infective Endocarditis, or Valve Prolapse

What are four causes of primary leaflet-related aortic regurgitation?

Shortening and retraction

What structural change is caused by rheumatic disease on the aortic valve leaflets?

Destruction

What structural damage does Infective Endocarditis cause to the aortic valve leaflets?

Aortic annular dilation, Marfan's, Aortic Dissection, Syphilis, or Ankylosing Spondylitis

What are five causes of secondary root-related aortic regurgitation?

Pulls the normal leaflets apart

How does a dilated aortic root cause central aortic regurgitation?

Diastole

During which phase of the cardiac cycle does blood leak backward from the aorta into the left ventricle in aortic regurgitation?

Eccentric hypertrophy

What specific structural left ventricular remodeling occurs in response to chronic volume overload in aortic regurgitation?

Precipitously drops

What happens to the aortic diastolic blood pressure in patients with severe chronic aortic regurgitation?

10 or even 0 mmHg

To what extreme values can the aortic diastolic blood pressure fall in severe aortic regurgitation?

Systolic blood pressure increases

What happens to the systolic blood pressure when a large stroke volume is ejected into the aorta in aortic regurgitation?

Wide pulse pressure

What is the mechanical driver of all legendary peripheral signs of chronic aortic regurgitation?

de Musset sign

Which peripheral sign of aortic regurgitation is characterized by bobbing or nodding of the head in time with the arterial pulse?

Corrigan pulse or Water-hammer pulse

Which peripheral sign of aortic regurgitation is characterized by a rapid, forceful pulse that suddenly collapses during diastole?