51e Approach to the Patient with a Heart Murmur

Question 1

Mechanisms of heart murmurs.

Answer 1

due to increased turbulence from accelerated blood flow through normal or abnormal orifices, flow through a narrowed or irregular orifice into a dilated vessel or chamber, or backward flow through an incompetent
valve, ventricular septal defect, or patent ductus arteriosus

Question 2

Gallavardin effect

Answer 2

The coarse systolic murmur of aortic stenosis (AS) may sound higher pitched and more acoustically pure at the apex.

Question 3

What is the grading system of heart murmurs?

Answer 3

A grade 1 murmur is very soft and is heard only with great
effort. A grade 2 murmur is easily heard but not particularly loud. A grade 3 murmur is loud but is not accompanied by a palpable thrill over the site of maximal intensity. A grade 4 murmur is very loud and is accompanied by a thrill. A grade 5 murmur is loud enough to be heard with only the edge of the stethoscope touching the chest, whereas a grade 6 murmur is loud enough to be heard with the stethoscope
slightly off the chest.

Question 4

Murmurs of grade 3 or greater intensity usually signify what?

Answer 4

important structural heart disease and indicate high

blood flow velocity at the site of murmur production.

Question 5

WHat can diminish the intensity of a heart murmur?

Answer 5

obesity, obstructive lung disease and a large pericardial effusion. The intensity of a murmur also may be misleadingly soft when cardiac output is reduced

Question 6

What causes an early systolic murmur?

Answer 6

Acute, severe MR

Question 7

What causes an acute, severe MR?

Answer 7

(1) papillary muscle rupture complicating acute myocardial infarction (MI), (2) rupture of chordae tendineae in the setting of myxomatous mitral valve disease, (3) infective endocarditis, and (4) blunt chest wall trauma.

Question 8

In acute, severe MR from papillary muscle rupture a murmur may be absent in up to which % of cases?

Answer 8

50%

Question 9

In acute, severe MR from papillary muscle rupture what papillary muscles might be involved?

Answer 9

posteromedial papillary muscle is involved 6 to 10 times more frequently than the anterolateral papillary muscle.

Question 10

Murmur associated with VSD?

Answer 10

A congenital, small muscular VSD may be associated with an early systolic murmur. It is localized to the left sternal border and is usually of grade 4 or 5 intensity.

Question 11

Murmur associated with large VSD?

Answer 11

holosystolic

Question 12

Murmur associated with Tricuspid regurgitation (TR)?

Answer 12

early systolic murmur; the murmur is soft (grade 1 or 2), is best heard at the lower left sternal border, and may increase in intensity with inspiration (Carvallo’s sign)

Question 13

What is the most common cause of a midsystolic murmur in an adult?

Answer 13

Aortic stenosis

Question 14

How do you differenciate an apical systolic murmur from MR from the murmur of AS?

Answer 14

The murmur of AS will increase in intensity, or become louder, in the beat after a premature beat, whereas the murmur of MR will have constant intensity from beat to beat. The intensity of the AS murmur also varies directly with the cardiac output.

Question 15

How is the murmur of AS?

Answer 15

Mid-systolic; is usually loudest to the right of the sternum in the second intercostal space (aortic area) and radiates into the carotids. Transmission of the midsystolic murmur to the apex, where it becomes higher-pitched, is common
(Gallavardin effect)

Question 16

How is the murmur of obstructive form of hypertrophic cardiomyopathy (HOCM)?

Answer 16

mid-systolic murmur that is usually loudest along the left sternal border or between the left lower sternal border
and the apex. The intensity of the murmur may vary from beat to beat and after provocative maneuvers but usually does not exceed grade 3.

Question 17

The obstructive form of hypertrophic cardiomyopathy (HOCM) will increase/decrease with which maneuvers?

Answer 17

classically will increase in intensity with maneuvers that result in increasing degrees of outflow tract obstruction, such as a reduction in preload or afterload (Valsalva, standing, vasodilators), or with an augmentation of contractility (inotropic stimulation). Maneuvers that
increase preload (squatting, passive leg raising, volume administration) or afterload (squatting, vasopressors) or that reduce contractility (β-adrenoreceptor blockers) decrease the intensity of the murmur.