Page 55 - Clinical Pearls in Cardiology

Arterial Pulse and Blood Pressure 43

Pulse deficit is calculated at the bedside by auscultating
and counting the number of first heart sounds (i.e. S1)
and by asking a second person to simultaneously count
the radial pulse rate. The difference between the two is
then calculated to get the pulse deficit.
20. What are the important causes of atrial fibrillation?
Atrial fibrillation occurs in many forms of heart disease,
particularly those diseases that are associated with
dilatation of the atria. Atrial fibrillation can result in
complications like congestive heart failure and systemic
thromboembolism. The mnemonic ‘smart chap’ can
be used to remember the common causes of atrial
fibrillation. Older the age, higher the incidence of atrial
fibrillation.
• Surgery—post-CABG, post-valvular surgery
• Medications—theophylline, caffeine, etc.
• Atherosclerosis—coronary artery disease
• Rheumatic heart disease—usually with mitral
stenosis
• Thyrotoxicosis
• Congenital heart disease—ASD, Ebstein’s anomaly
• Hypertensive heart disease—most common cause of
atrial fibrillation
• Alcohol consumption—holiday heart syndrome
• Pulmonary and pericardial diseases—pneumonia,
pericarditis, etc.
In about 50% of patients with atrial fibrillation, no
obvious cause is recognized. This entity is referred to as
“lone atrial fibrillation”.
21. What is blood pressure?
Blood pressure is the lateral force excerted by the column
of blood within a blood vessel on the vascular wall
surrounding it. The actual value of blood pressure is