Final answer:
A heart murmur is caused by turbulent blood flow, often resulting from heart valve irregularities. Systolic murmurs occur during heart muscle contraction and can sound like a whoosh, whereas diastolic murmurs occur during relaxation and have a blowing sound. Murmurs are graded on a scale from 1 to 6, with 1 being the least serious and 6 the most severe.
Step-by-step explanation:
Murmur is caused by the turbulent flow of blood through the heart, which can be due to various heart valve anomalies or other abnormalities.
A systolic murmur is heard during the part of the heartbeat when the heart muscle contracts (systole) and pumps blood out of the chambers. It can sound like a whooshing or swishing noise, and can be caused by conditions such as mitral valve prolapse, ventricular septal defect, or outflow obstructions.
Conversely, a diastolic murmur occurs during the relaxation phase of the heart cycle (diastole) when the heart fills with blood. This murmur tends to have a rhythmic blowing sound and can be an indication of conditions like mitral stenosis or aortic regurgitation.
Heart murmurs are graded on a scale from 1 to 6, based on their intensity, with 1 being hardly detectable and 6 being the most severe. The detection and recording of murmurs can be done using electronic stethoscopes that produce phonocardiograms or auscultograms.