QUANTITATIVE AND QUALITATIVE CHANGES OF HEART TONES (HEART SOUNDS)

QUANTITATIVE CHANGES

 

DECREASING OF 1ST TONE

 - ON THE HEART APEX

Insufficiency of mitral and aortal valves 

Due to incomplete closing of the valves, it results in a back flow of blood. Hence leading to a decrease of blood pressure in the Left Ventricle. This results in weakening of the muscular and valvular component, therefore decreasing the 1st Tone (heart sound).

Aortal stenosis 

Due to incomplete opening of the semilunar valve, it results to a slow unloading of the blood, that eventually decrease the intraventricular pressure and attenuate the 1st Tone.

Diffuse defects of heart muscle

Dystrophy, Cardiosclerosis, Myocarditis 

Hypertrophy of the Left ventricle 

 

- OVER THE BASIS OF XIPHOID PROCESS

Insufficiency of tricuspid and pulmonary artery valves

Weakening the muscular and valvular component of Right Ventricle.( Insufficiency - incomplete closing of any valve causing blood to back flow )

 

INCREASING OF 1ST TONE 

- OVER THE HEART APEX

Mitral stenosis 

Due to incomplete opening of the Left atrioventricular valve, it causes less blood to flow into Left Ventricle, thereby decreasing the left ventricular stretch. 

Low ventricular stretch means muscles are weak and it is easy to contract during the beginning of systole. Hence the left ventricle contracts fast by giving a high, increased 1st Tone.

Tachycardia and Extrasystoles are some clinical symptoms observed due to small diastolic filling of the ventricle.

DECREASING OF 2ND TONE

- OVER THE AORTA 

Aortal insufficiency 

Destruction of valve cusps or decreasing their ability to fluctuate (due to a cicatricial consolidation).

- OVER THE PULMONARY ARTERY

Insufficiency of pulmonary valve 

Incomplete closing of the semilunar valve and a low blood pressure inside pulmonary artery.

INCREASING OF 2ND TONE

- OVER THE AORTA

Increased blood pressure inside aorta

Arterial hypertension, performance of heavy physical activity, mental excitation are some usual reasons.

Due to this high pressure during diastole, the valvular cusps close by slamming with high force. 

Sclerosis of aortal valve

Consolidation of walls of aorta

Atherosclerosis, syphilitic mesoaortitis.

 

 

 QUALITATIVE CHANGES