1. Hypertrophic Subaortic Stenosis Complicated by High Degree Heart Block: Successful Treatment with an Atrial Synchronous Ventricular Pacemaker 
Allen D. Johnson, M.D., Pat O. Daily, M.D. 
CHEST 
Volume 67, Issue 4, Pages (April 1975)
DOI: /chest
Copyright © 1975 The American College of Chest Physicians Terms and Conditions

2. FIGURE 1
Echocardiogram. Despite a long preceding diastolic filling period, following atrial systole (P2), the diastolic diameter of the left ventricular cavity increases from 37 mm to 44 mm simultaneously with a prominent A deflection of the anterior mitral leaflet. Note the increased septal thickness and SAM of the anterior leaflet of the mitral valve, both characteristic of hypertrophic subaortic stenosis.
AML = Anterior Mitral Leaflet. A Sys = Atrial Systole. LVES = Left Ventricular Endocardial Surface. PLVWE = Posterior Left Ventricular Endocardial Surface. PML = Posterior Mitral Leaflet. RVES = Right Ventricular Endocardial Surface. SAM = Systolic Anterior Motion.
CHEST  , DOI: ( /chest )
Copyright © 1975 The American College of Chest Physicians Terms and Conditions

3. FIGURE 2
Left ventricular and left brachial artery pressures recorded simultaneously during ventricular pacing, R-R interval 700 msec. Beats preceded by a P wave with a P-R interval from .16 sec to .36 sec (R1, R2, R7) have no systolic gradient. Note also that following premature beat R6, arterial pressure at the onset of systole is least in beat R7.
CHEST  , DOI: ( /chest )
Copyright © 1975 The American College of Chest Physicians Terms and Conditions

4. FIGURE 3
Simultaneous electrocardiogram, indirect carotid pulse tracing, and apex phonocardiogram during atrial triggered ventricular pacing, followed by fixed rate ventricular pacing. Note beat-to-beat changes in systolic murmur and character of carotid pulse depending upon presence of preceding atrial contractions (P, P1, P2, P3). AG = Atrial Gallop.
CHEST  , DOI: ( /chest )
Copyright © 1975 The American College of Chest Physicians Terms and Conditions