Rheumatic fever
Rheumatic fever is a post streptococcal autoimmune disorder. Many of the features of rheumatic fever were described by Sydenham as early as 17th century. Rheumatic fever is said to lick the joints and bite the heart because polyarthritis, the commonest manifestation in adults, leaves no sequelae while carditis often leaves back disabling sequelae.
Antibodies to antigens of group A beta hemolytic streptococci (GABHS) initiate autoimmune injury to human tissues. Aschoff bodies are the pathognomonic histologic features of rheumatic fever. They appear as early as 2 weeks from the onset of rheumatic fever.
Jones criteria were proposed for the diagnosis of rheumatic fever in 1944. Jones criteria have undergone various modifications and revisions since then. Major manifestations are carditis, polyarthritis, chorea, erythema marginatum and subcutaneous nodules. Supporting evidence for recent streptococcal infection is also needed. World Health Organization (WHO) criteria 2002-2003 for diagnosis of rheumatic fever and rheumatic heart disease is based on the 1992 Revised Jones Criteria.
Differentiation of regular cannon waves from prominent v waves or cv waves of tricuspid regurgitation
Cannon waves have the characteristics of a wave and are seen as flicking waves, while v waves have a surging nature. Cannon waves occur during atrial systole and have a shorter duration than the v wave of tricuspid regurgitation which occurs during ventricular systole.
Irregular cannon waves in complete heart block
Irregular cannon waves in complete heart block are irregular in both timing and amplitude. P occurring later in systole has a taller cannon wave as there is more time for atrial filling. Moreover, during early part of the ventricular systole, atrial pressure drops due to descend of the tricuspid valve.
Tricuspid regurgitation jet (Doppler) in complete heart block and junctional rhythm
Tricuspid regurgitation jet can show a notch during atrial systole when the P waves occur during systole. This can be seen as a regular feature in all cycles in junctional rhythm while it is varying in complete heart block. The notch may be visible only if the tricuspid regurgitation jet envelope is complete and the right ventricular pressures normal as in non-hypertensive tricuspid regurgitation.
Chatterjee phenomenon
Post pacing T wave inversion has been called Chatterjee phenomenon.