For the following cardiac abnormalities, select the characteristic JVP finding.Complete heart block: (A) Cannon a wave, (B) prominent x descent, (C) Kussmaul's sign, (D) slow y descent
Answer is A. Large a waves occur with increased resistance to filling (tricuspid stenosis, pulmonary hypertension) or when the right atrium contracts against a tricuspid valve closed by right ventricular systole (Cannon a waves) in complete heart block or other arrhythmias.