Heart Cycle

Question 1

A wave

Answer 1

Atrial contraction

Absent: Atrial Fibrillation

Enlarged: Tricuspid Stenosis, Pulmonic Stenosis, Pulmonary Hypertension, Complete AV Block.

S4 occurs when atria contract against stiff ventricle (apex)

Question 2

X descent

Answer 2

Atrial relaxation during Ventricular Rapid Ejection

(After S1 –apex)

Absent: Tricuspid Regurgitation

Steep/Rapid: Constrictive Pericarditis

Question 3

V wave

Answer 3

Atrial Filling during late Ventricular ejection

Peaks right at S2 (Base)

Absent: Cardiac Tamponade

Enlarged: Tricuspid Regurgitation

Question 4

Y descent

Answer 4

Rapid Atrial Emptying (Passive Ventricular Filling)

S3 (apex) due to Volume Overload

Steep/Rapid: Constrictive Pericarditis

Question 5

S4

Answer 5

Atria Contract Against Stiff Ventricle

@ Apex

Question 6

S1

Answer 6

AV valves (tricuspid and mitral) close

@ Apex

(After A wave; during X descent)

Question 7

S2

Answer 7

Aortic and Pulmonic valves close

@ Base

(During V wave)

Fixed S2 Split: ASD
S2 Split: Pulmonic Stenosis
Paradoxical S2 Split (expiration, Aortic following Pulmonic): Aortic Stenosis

Question 8

S3

Answer 8

Volume Overload during

Passive, Rapid Ventricular Filling
(During Rapid Atrial Emptying)

@ Apex

Common in Tricuspid Regurgitation, Mitral Regurgitation