Cardiac- Arterial Pulses And Rate + Rhythm

Question 1

Arterial pulses- what to assess when taking a pulse

Answer 1

• rate
• rhythm
• volume: degree of pulsation
• character: impression of pulse waveform

Question 2

Arterial pulse exam sequence- radial pulse

Answer 2

• Place the pads of your index and middle fingars over the right wrist, just lateral to the flexor carpi radialis tendon
• Assess the rhythm of the pulse and count the number over 15 seconds, multiply by 4 to obtain the rate in beats perminute (bpm)
• To detect a collapsing pulse: first, check that the patient has no shoulder or arm pain or restriction on movement;
• next,feel the pulse with the base of your fingers, then raise the patient’s arm vertically above their head
• Palpate both radial pulses simultaneously,assessing anydelay between the two.

Question 3

Arterial pulses- brachial pulses

Answer 3

• Cup your hand under the elbow and use your thumb to palpate the pulse in the antecubital fossa, just medial to the biceps tendon
• Use your right thumb for the patients right arm and your left thumb for the patient’s left arm.
• Assess the character and volume of the pulse.

Question 4

Arterial pulses

Answer 4

• Explain what you are going to do.
• With the patient semi-recumbent, place the tips of your fingers between the larynx and the anterior border of the sternocleidomastoid muscle
• Palpate the pulse gently to avoid a vagal reflex, and never assess both carotids simultaneously.
• Listen for bruits over both carotid arteries, using the diaphragm of your stethoscope in held inspiration.

Question 5

Rate- common causes Brady/tachycardia

Answer 5

• The most common causes of bradycardia are medication, athletic conditioning and sinoatrial or AV node dysfunction
• The most common cause of tachycardia is sinus tachycardia

Question 6

Rhythm

Answer 6

• The pulse may be regular or irregular.
• Sinus rhythm is regular but heart rate varies with the respiratory cycle, particularly in children, young adults or athletes (sinus arrhythmia).
• During inspiration, parasympathetic tone falls and the heart rate increases
• on expiration, the heart rate decreases.
• With intermittent extrasystoles or second-degree atrioventricular block, there may be an underlying regularity to the pulse, interspersed with periods of irregularity (sometimes referred to as ‘regularly irregular’).
• In AF the pulse has no appreciable pattern and is often described as ‘irregularly irregular’
• The rate in AF depends on the number of beats conducted by the AV node.
• Untreated, the ventricular rate may be very fast (up to 200 bpm).
• The variability of the pulse rate (and therefore ventricular filling) explains why the pulse volume varies and there may be a pulse deficit, with some cycles not felt at theradial artery.
• The pulse deficit can be calculated by counting theradial pulse rate and subtracting this from the apical heart rate, assessed by auscultation.

Question 7

Haemodynamic effects of respiration

Answer 7

• pulse/heart rate: accelerates on inspiration and slows on expiration
• systolic blood pressure: falls on inspiration, rises on expiration
• JVP: falls on inspiration and rises on expiration
• second heart sound: splits on inspiration and fuses on expiration

Question 8

Pulses- causes of large and small pulse volume

Answer 8

• The ventricles fill during diastole. Longer diastolic intervals are associated with increased stroke volume, which is reflected by increased pulse volume on examination.
• Abnormalities of pulse volume and character are highly subjective, however, and tend to have poor inter observer agreement.
• A large pulse volume is a reflection of a large pulse pressure, which can occur in physiological states such as exercise or pregnancy, or in pathological conditions such as anaemia, thyrotoxicosis or aortic regurgitation.
• Low pulse volume may result from severe heart failure and conditions associated with inadequate ventricular filling such as hypovolaemia, cardiac tamponade and mitral stenosis.

Question 9

Pulse volume and character- asymmetrical pulses, coarctation

Answer 9

• Asymmetric pulses may represent occlusive PAD or stenosis and, rarely, aortic dissection.
  -Coarctation is a congenital narrowing of the aorta, usually distal to the left subclavian artery (Fig. 4.9); it may produce reduced-volume lower limb pulses, which are alsodelayed relative to the upper limb pulses (radiofemoral delay).
• In adults, coarctation usually presents with hypertension and heart failure.
• A slow-rising pulse has a gradual upstroke with a reduced peak occurring late in systole, and is a feature of stenosis
• A collapsing pulse may occur with severe aortic regurgitation.
• The peak of the pulse wave arrives early and is followed by a rapid fall in pressure as blood flows back into the left ventricle, resulting in a wide pulse pressure (systolic- diastolic blood pressure >80 mmHg).
• This rapid fall imparts the ‘collapsing’ sensation, and is exaggerated by raising the patient’s arm above the level of the heart
• Pulses bisferiens, an increased pulse with a double systolic peak separated by a distinct mid-systolic dip, is classically produced by concomitant aortic stenosis and regurgitation.
• Pulsus alternans, beat-to-beat variation in pulse volume with a normal rhythm, may occur in advanced heart failure.
• Both of these signs are rare, however, and of limited relevance in contemporary practice.
• Pulsus paradoxus is an exaggeration of the normal variability of pulse volume with breathing.
• Pulse volume normally increases in expiration and decreases during inspiration due to intrathoracic pressure changes affecting venous retum to the heart.
• This variability is exaggerated when ventricular diastolic filling is impeded by elevated intrapericardial pressure.
• This is usually due to accumulation of pericardial fluid (cardiac tamponade) but can occur to a lesser extent with pericardial constriction and in acute severe asthma.
• If suspected, pulsus paradoxus can be confirmed using a blood pressure(BP) cuff
• a fall of greater than 10 mmHg between the cuff pressure at which Korotkoff sounds appear in expirationonly and the cuff pressure at which Korotkoff sounds persist throughout the respiratory cycle is diagnostic.