Nursing practice often involves undertaking procedures about which there is debate or uncertainty. In Practice Question we ask experts to determine how nurses should approach these situations
Q. I have been asked to help measure the apex and radial pulse. What are they and why is it necessary to measure both?
A. Simultaneous measurement of the apex beat and radial pulse is usually done when a patient is in atrial fibrillation as it indicates the efficacy of drug therapy.
The apex is the tip or summit of an organ; the apex beat is the heart’s impact against the chest wall during systole. It is primarily due to recoil of the apex of the heart as blood is expelled during systole and correlates with left ventricular contraction (Scott and MacInnes, 2006). The normal location of the apex beat is the fifth or sixth intercostal space in the mid clavicular line, with the patient supine at 45º (Scott and MacInnes, 2006).
Atrial fibrillation is common (Jevon, 2009), affecting around 10% of people aged over 70 (Goodacre and Irons, 2008). Causes include valvular heart disease, ischaemic heart disease, dilated cardiomyopathy, aortic stenosis, hypertension, pericarditis, cardiac surgery, thyrotoxicosis, pulmonary disease, alcohol excess and alcohol withdrawal.
It is characterised by an irregular pulse (Jevon, 2009), with atria discharging at 350-600 impulses/min (Bennett, 2006). These impulses bombard the atrioventricular junction and are intermittently conducted to the ventricles, resulting in an irregular QRS rhythm (Jevon, 2009).
The ventricular rate depends on the degree of atrioventricular conduction.
In atrial fibrillation, the atria fibrillate rather than contract in a controlled manner, leading to a fall in stroke volume and cardiac output (Jevon, 2009). Classic electrocardiogram features include a wavy, irregular baseline of ‘f’ (fibrillation) waves and no normal ‘P’ waves, with an irregular and often rapid ventricular response (Goodacre and Irons, 2008).
Controlling the ventricular response in atrial fibrillation benefits patients in terms of symptoms, quality of life and prevention of conditions such as tachycardia induced cardiomyopathy (Jevon, 2009).
Digoxin, calcium channel blockers and beta-blockers can be used to control the ventricular rate. Digoxin is often prescribed for chronic atrial fibrillation (Singer and Webb, 2005); it helps to control the ventricular rate, especially with associated heart failure (Jowett and Thompson, 1995).
Apex and radial pulse
Checking the radial pulse alone is unreliable when assessing the ventricular rate in people with atrial fibrillation. When the ventricular rate is rapid, some contractions may not be strong enough to transmit an arterial pulse wave through the peripheral artery, resulting in an apex-radial pulse deficit (Lip, 1993).
Simultaneous monitoring of the apex beat and radial pulse is advisable in patients with atrial fibrillation as it helps determine the ventricular rate more reliably and ascertain whether an apex beat-radial pulse deficit is present (Jevon, 2007). However, routine apex beat-radial pulse monitoring is not usually undertaken if ECG monitoring is available.
It is helpful to monitor the apex beat and apex-radial pulse deficit when a patient is prescribed digoxin, to assess the drug’s effectiveness. The maintenance dose is usually determined by the ventricular rate at rest; this should not be allowed to fall below 60bpm except in special circumstances, such as when beta-blockers are being given.
Philip Jevon, PGCE, BSc, RN, is resuscitation officer/clinical skills lead, Manor Hospital, Walsall
Measurement of the apex and radial pulse by two nurses
- Explain the procedure to the patient; obtain consent.
- Ask the patient to rest for 15 minutes before the procedure.
- Assemble equipment (stethoscope, observation chart, watch, blue and red pens).
- Ensure patient privacy and dignity, expose their chest.
- Ask the patient to breathe normally and to relax.
- First nurse: palpate the radial pulse.
- Second nurse: using the diaphragm of the stethoscope, locate the apex beat, usually
- just outside the midclavicular line in the fifth or sixth left intercostal space.
- Agree a start time and count the radial pulse and apex beat simultaneously for one minute.
- Document the results, apex in red and radial in blue. A wide apex-radial pulse deficit indicates inefficient cardiac contraction (Jevon, 2009).
- If the apex beat is <60bpm, withhold prescribed medication, for example digoxin, and inform medical staff, unless medical instructions indicate otherwise.
- If the apex beat is >60bpm, administer medication as prescribed.
Sources: Endacott et al (2009); Jevon (2007)
Bennett DH (2006) Cardiac Arrhythmias. Oxford: Butterworth Heinemann.
Endacott R et al (2009) Clinical Nursing Skills: Core and Advanced. Oxford: Oxford University Press.
Goodacre S, Irons R (2008) Atrial arrhythmias. In: Morris et al (eds) ABC of Clinical Electrocardiography. Oxford: Blackwell Publishing.
Jevon P (2009) ECGs for Nurses. Oxford: Wiley-Blackwell.
Jevon P (2007) Cardiac monitoring part 4: monitoring the apex beat. Nursing Times; 103: 4, 28-29.
Jowett N, Thompson D (1995) Comprehensive Coronary Care. London: Scutari Press.
Lip G (1993) ABC of Atrial Fibrillation. London: BMJ Publishing Group.
Scott C, MacInnes J (2006) Cardiac patient assessment: putting the patient first. British Journal of Nursing; 15: 9, 502-508.
Singer M, Webb A (2005) Oxford Handbook of Critical Care. Oxford: Oxford University Press.