S1 VARIATIONS Flashcards
1
Q
- S1 is softer than S2 at base, and usually louder at apex
A
Normal
2
Q
- Tachycardia
- Rhythms with short PR intervals
- High cardiac output states (exercise, hyperthyroidism, etc.)
- Mitral stenosis (valve still open at beginning of LV systole and closes quickly)
A
Accentuated S1
3
Q
- 1st degree heart block (atria/ ventricles beating independently)
- Left bundle branch block
- Myocardial infarction due to weak ventricle contraction
- Acute aortic regurgitation (mitral valve closes before ventricle contraction)
A
Diminished S1
4
Q
- Complete heart block (atria and ventricle beating independently)
- Any totally irregular (atrial fibrillation; mitral valve in varying positions before ventricle contraction)
A
Varying S1
5
Q
- Delayed closure of tricuspid valve
- Prominent when RV contraction is delayed (right bundle branch block and left premature
contractions)
A
Split S1