Where it is
In the mediastinum, between the lungs and behind the sternum, with its apex pointing down and to the left at about the fifth intercostal space, midclavicular line.
What it does
The right atrium and ventricle pump blood to the lungs; the left atrium and ventricle pump it to the body. The left ventricle has the thickest wall because it pumps against the highest pressure.
Clinical relevance
- The point of maximal impulse (PMI) is felt at the apex, fifth intercostal space, midclavicular line.
- Left ventricular failure causes pulmonary congestion; right ventricular failure causes systemic edema.
- Pericardial effusion and tamponade compress the heart: muffled heart sounds, JVD and hypotension (Beck's triad).
Nursing focus
- Count the apical pulse for one full minute when the rhythm is irregular or before cardiac medications.
- Monitor for dysrhythmias with continuous ECG in acute cardiac conditions.