AUSCULTATION IN CARDIOVASCULAR SYSTEM EXAMINATION:
HEART SOUNDS IN CARDIOVASCULAR SYSTEM EXAMINATION:
IN CARDIOVASCULAR SYSTEM EXAMINATION:
Normally, there are 4 heart sounds. However, clinically, only two heart sounds can be auscultated in a majority of people. The 1st heart sound best heard in the mitral area and the 2nd sound is best auscultated in the aortic and pulmonary areas.
This heart sound cause by the closure of the mitral and tricuspid valves. Splitting may heard during inspiration and is normal.
A loud S1(tapping apex) can hear in cases of mitral stenosis, because the stenotic valves open maximally at the end of diastole and then shut rapidly, tachycardia and high cardiac output states like anaemia and hyperthyroidism.
A soft S1 hear if the diastolic time prolong, i.e. in cases of mitral incompetence, because the mitral leaflets fail to close properly, calcified mitral valves and first degree heart block.
A variable S1 can hear in complete heart block and atrial fibrillation.
This heart sound cause by the closure of aortic (A2) and pulmonary (P2) valves.
A soft A2 hear in aortic stenosis whereas a loud A2 is heard in hypertension and transposition.
A soft P2 hear in pulmonary stenosis whereas a loud P2 can be heard in pulmonary hypertension.
Splitting a normal phenomenon occurring during respiration. It best hear in the pulmonary area.
Wide splitting may indicate pulmonary stenosis, mitral regurgitation, right bundle branch block or ventricular septal defect. Wide fixed splitting seen in cases of atrial septal defect.
Reverse splitting seen in cases of aortic stenosis, patent ductus arteriosus and left bundle branch block.
Single 2nd heart sound heard in severe aortic or pulmonary stenosis, Eisenmenger’s syndrome and Fallot’s tetralogy.
This is a low-pitched heart sound, which may hear with the bell of the stethoscope. It occurs immediately after the second sound.
A loud S3 occurs when rapid ventricular filling occurs in a dilated left ventricle, as in mitral regurgitation and ventricular septal defect or when the left ventricular function is poor, as seen in dilated cardiomyopathy and post- Myocardial infarction. It more high-pitched and occurs early in restrictive cardiomyopathy and constrictive pericarditis (pericardial knock).
This heart sound occurs just before the first heart sound. It dull and low-pitch and is best heard with the bell of the stethoscope. An audible 4th heart sound observe in cases of aortic stenosis and hypertensive heart disease.
When the 3rd or 4th sound occur with tachycardia (heart rate > 100/min), it may give the effect of galloping hooves. In such cases (e.g. pulmonary embolism), discrimination between the 3rd and 4th sounds is not possible and they may summate and seem like a single sound. This call a summation gallop.
MURMURS IN CARDIOVASCULAR SYSTEM EXAMINATION:
Murmurs abnormal heart sounds caused by turbulence of blood flow within the heart and great blood vessels, usually caused by valve disease, or sometimes by increased flow through a normal valve.
They characterized on the basis of 4 parameters- Location, Loudness, Timing and Quality.
LOCATION denotes the site of origin of the murmur.
LOCATION AND TYPE OF MURMUR:
- Near cardiac apex -Near cardiac apex
- Left sternal edge -Tricuspid
- Right 2nd intercostal space -Aortic
- Left 2nd intercostal space -Pulmonary
LOUDNESS signifies the degree of turbulence, which determine by the volume and velocity of blood flow, but not the severity of the cardiac pathology. Murmurs have graded based on their loudness as follows:
GRADE AND NATURE OF MURMUR:
- I (1/6): Very soft, heard with effort and after listening for a while
- II (2/6): Soft, but audibly detectable immediately
- III (3/6): Clearly audible and moderately loud, but no palpable thrill
- IV (4/6): Clearly audible, with palpable thrill
- V (5/6): Audible, with thrill, and can hear with stethoscope only partially touching chest, or away from involved site
- VI (6/6): Audible without placing stethoscope on chest
QUALITY signifies the frequency of the murmur and is described as low-, medium-, or high-pitch.
TIMING denotes the phase of systole (mid-systolic, pansystolic or late systolic) or diastole (early diastolic, mid-diastolic or pre-systolic) during which the murmur is audible. Continuous murmurs are audible throughout the cardiac cycle.
Mid Systolic (Ejection) Phase:
1.AORTIC: Turbulence in the left ventricular outflow tract during ejection. Follows opening of aortic valve, loudening in mid-systole.
- HEARD IN: Aortic area with radiation to neck
- CONDITIONS SEEN IN: Aortic stenosis, PDA, Coarctation of aorta hypertrophic cardiomyopathy
2.PULMONARY: Turbulence in the right ventricular outflow tract during ejection. Follows opening of pulmonary valve, loudening in mid-systole.
- HEARD IN: Pulmonary area
- CONDITIONS SEEN IN: Pulmonary stenosis, Fallot’s tetralogy, pulmonary hypertension, ASD, High output states.
Pansystolic Phase:
- NATURE: Murmur is audible throughout systole. Caused by incompetent atrioventricular valves or VSDs
- HEARD IN:
1.Firstly, Cardiac apex radiating to left axilla :CONDITIONS SEEN IN: Mitral incompetence
2. Secondly, Lower left edge of sternum: CONDITIONS SEEN IN: Tricuspid incompetence, VSD
Late Systolic Phase:
1.Firstly, Cardiac apex (Mitral valve prolapse) :CONDITIONS SEEN IN: Tricuspid incompetence, VSD
2. Secondly, Lower left sternal border (Tricuspid valve prolapse): CONDITIONS SEEN IN: Mitral valve prolapse, tricuspid valve prolapse, papillary muscle dysfunction
Early Diastolic Phase:
- NATURE: Begin after 2ndheart sound and decline in sound; they are high-pitched. Occur due to incompetent aortic and pulmonary valves.
- HEARD IN:
1.Firstly, AORTIC: Aortic area radiating to left sternal edge: CONDITIONS SEEN IN: Aortic incompetence
2.Secondly, PULMONARY: Pulmonary area :CONDITIONS SEEN IN: Pulmonary incompetence
Mid Diastolic Phase:
- NATURE: Begin late after 2nd heart sound and occur due to turbulent flow through the valves.
- HEARD IN:
1.Firstly, Cardiac apex :CONDITIONS SEEN IN: Mitral stenosis, Austin Flint murmur of Aortic incompetence, VSD, Mitral incompetence
2.Secondly, Lower left edge of sternum :CONDITIONS SEEN IN: Tricuspid stenosis, ASD, Tricuspid imcompetence
Pre-systolic Phase:
1.Firstly, Cardiac apex :CONDITIONS SEEN IN: Mitral stenosis
2.Secondly, Lower left edge of sternum: CONDITIONS SEEN IN: Tricuspid stenosis
Continuous Phase:
CONDITIONS SEEN IN: PDA, Ruptured sinus of Valsalva
VENOUS HUM
This a soft, continuous and low-pitch murmur occurring due to hyperkinetic jugular venous flow, audible at the base of the heart. It emphasize in early diastole and commonly hear in infants.
MAMMARY SOUFFLE
This a soft, continuous murmur, emphasize during systole, occurring in the third month of pregnancy. It is audible over the mammary area and second intercostal spaces.
SYSTOLIC CLICKS
They high-pitch sounds coming in early systole due to excessive ejection of blood into the vessels from the ventricles.
Clicks are of 2 types:
- AORTIC: It transmit to the cardiac apex and is heard in cases of Aortic stenosis, aortic aneurysm, aortic incompetence and aortic coarctation.
- PULMONARY: It is audible best during the phase of inspiration and hear in cases of pulmonary stenosis, pulmonary hypertension and pulmonary arterial dilatation.
OPENING SNAP
It a loud, sharp, high-pitch sound occurring due to sudden tensing of the mitral/tricuspid valves heard between the 2nd and 3rd heart sounds, during early diastole. It hear in cases of mitral/tricuspid stenosis and indicates a non-calcified valve.
PERICARDIAL FRICTION RUB
It a scratching type of high-pitched sound heard during systole and diastole over the left precordium. This occurs in pericardial effusion due to the movement of the exudate in the pericardial cavity as a result of the beating of the heart. It best hear in maintained expiration, in the sitting position with the patient leaning slightly forward.