arrhythmia Flashcards
what is the first heart sound (S1) caused by?
Closure of mitral and tricuspid valves
what does S1 sound like in mitral regurgitation and stenosis?
Soft if long PR or mitral regurgitation
Loud in mitral stenosis
what is S2 caused by?
Closure of aortic and pulmonary valves
what does S2 sound like in aortic stenosis and inspiration?
Soft in aortic stenosis
Splitting during inspiration is normal
what is S3 caused by?
Caused by diastolic filling of the ventricle
when is S3 considered normal?
Considered normal if < 30 years old (may persist in women up to 50 years old)
where can S3 be heard?
in left ventricular failure (e.g. dilated cardiomyopathy)
constrictive pericarditis (called a pericardial knock)
mitral regurgitation
what is S4 caused by?
Caused by atrial contraction against a stiff ventricle
In HOCM, a double apical impulse may be felt as a result of a palpable S4
where can S4 be heard?
in aortic stenosis, HOCM, hypertension
what is heart block?
an abnormal heart rhythm where the heart beats too slowly (bradycardia).
In this condition, the electrical signals that tell the heart to contract are partially/ completetly blocked between the upper chambers (atria) and the lower chambers (ventricles)
what is first-degree heart block?
PR interval > 0.22s every atrial depolarisation is followed by ventricle contraction
what are the signs, symptoms and treatment of first-degree heart block?
asymptomatic and no treatment
what investigations are carried out to diagnose first-degree heart block?
ECG, drug screen and electrolytes
what is second-degree heart block?
type 1 (Mobitz I, Wenckebach):
- progressive prolongation of the PR interval until a dropped beat occurs
- type 2 (Mobitz II): PR interval is constant but the P wave is often not followed by a QRS complex
what are the symptoms and treatment for second-degree heart block?
Light-headedness
Dizziness
Syncope
Mobitz II
pacing (CRT device sends electrical signals to the ventricles to make them pump together the way they should)
Monitor Mobitz l
