Cardiac cycle

It refers to all events that occur from the beginning of one heartbeat to the beginning of the next.

The phase of the heartbeat where the heart ventricles are relaxed and fill with blood.

The phase of the heartbeat where the heart ventricles contract and pump blood into the: aorta (LV) and pulmonary artery (RV).

<p>Reciprocal of heart beat= 1/72=0.1388 mins/beat= 0.83 secs/beat.</p> Signup and view all the answers

<p>1/72=0.01388 mins/beat= 0.833 secs/beat. Systole= 0.5, Diastole= 0.3 approx.</p> Signup and view all the answers

<ol> <li>Filling phase- diastole and atrial systole</li> <li>Isovolumetric contraction- systole</li> <li>Outflow phase- systole/ early diastole</li> <li>Isovolumetric relaxation- diastole</li> </ol> Signup and view all the answers

<ol> <li>Passive filling - atria and ventricles relaxed, blood flows from the vena cava and pulmonary veins into the right and left atria and then into the ventricles.</li> <li>Atrial contraction - atrial depolarization (P wave) causes the atria to contract, forcing blood into the ventricles and completing the EDV.</li> </ol> Signup and view all the answers

<ol> <li>As atrial contraction completes, atrial pressure begins to fall.</li> <li>This reverses the pressure gradient across the AV valves, causing them to close (S1).</li> <li>At this point, ventricular depolarization (QRS complex) is halfway through and the ventricles contract, rapidly building up pressures inside the ventricles.</li> <li>This phase is referred to isovolumetric contraction because no blood is ejected (all valves are closed) and ventricular volume is unchanged.</li> </ol> Signup and view all the answers

<ol> <li>Once the pressure in the ventricles exceeds the pressure in the aorta/pulmonary trunk the aortic and pulmonary valves open, allowing blood to be pumped from the heart into the great arteries.</li> <li>At the end of systole ventricles begin to relax which decreases the pressure in the ventricles compared to in the aorta - the aortic and pulmonary valves close (S2)</li> </ol> Signup and view all the answers

<ol> <li>At the end of the outflow phase both sets of valves are closed again.</li> <li>Then ventricles begin to relax, reducing the pressure in the pressure in the ventricles so the AV valves open.</li> <li>Ventricles begin to fill with blood and the cycle starts again.</li> </ol> Signup and view all the answers

<p>It is caused by the closure of mitral and tricuspid valves, marks the beginning of systole.</p> Signup and view all the answers

<p>It is caused by closure of aortic and pulmonary valves, marks the end of systole and beginning of diastole.</p> Signup and view all the answers

<ol> <li>During inspiration, the intrathoracic pressure drops, which increases the venous return to the right side of the heart.</li> <li>This increased volume increases right ventricular ejection time during contraction, thus meaning that the pulmonary valve may take longer to shut than the aortic valve.</li> <li>This causes a split in the valve sounds during inspiration.</li> </ol> Signup and view all the answers

<ol> <li>It is an early diastolic low frequency filling sound which occurs immediately after S2; best heard at the apex.</li> <li>It is related to the acceleration and deceleration of blood during early passive filling of the ventricle.</li> <li>It is referred to as a diastolic murmur in some cases.</li> </ol> Signup and view all the answers

<ol> <li>In a healthy child or young adult with no evidence of heart disease, it is physiological and a normal finding.</li> <li>In an older patient with previous history of heart disease, it could be pathological- due to left ventricular dysfunction. They should be referred for an ECG.</li> </ol> Signup and view all the answers

<p>If there is a physiological splitting of the S2 sound during inspiration only, it means the finding is physiological- meaning normal.</p> Signup and view all the answers

<ol> <li>It is a late diastolic low frequency filling sound which occurs shortly before S1; best heard at the apex.</li> <li>Due to atrial contraction causing rapid blood flow to a stiff ventricle (decreased compliance)</li> <li>Common causes include MI, hypertension and aortic stenosis (almost always pathological).</li> </ol> Signup and view all the answers

<p>Myocardial ischaemia, hypertension and aortic stenosis (almost always pathological)</p> Signup and view all the answers

<p>2nd right intercostal space, sternal edge</p> Signup and view all the answers

<p>2nd left intercostal space, sternal edge</p> Signup and view all the answers

<p>4th left intercostal space, sternal edge</p> Signup and view all the answers

<p>5th left intercostal space, midclavicular line. - Apex beat can be palpated here</p> <ul> <li>Cardiomegaly often shifts the apex beat to the left</li> </ul> Signup and view all the answers

<p>Stretch and recoil of arteries keep the blood moving forward in diastole and prevent the arterial pressure from falling, despite ventricular pressure being close to 0.</p> Signup and view all the answers

<ol> <li>‘a’ - atrial contraction</li> <li>‘c’ - bulging of tricuspid valve into atrium during ventricular contraction</li> <li>‘v’ - rise of atrial pressure during atrial filling: release as AV valves open</li> </ol> Signup and view all the answers

<ol> <li>A normal JVP is no more than 3 cm vertically above the sternal angle when the patient is lying at a 45 degree angle.</li> <li>The estimation of Jugular venous pressure (JVP) is an indirect estimate of right atrial pressure (central venous pressure).</li> <li>An elevated JVP is one of the sign of heart failure.</li> </ol> Signup and view all the answers