Arrythmias and AV block

Question 1

what are the 6 major causes of AV block

Answer 1

1. Increased vagal tone
   - lightheaded, sweaty, leads to simple syncope
2. Fibrosis and sclerosis of conduction system
3. IHD
4. Cardiomyopathy and myocarditis
5. Congenital heart disease
6. Familial AV Block

Question 2

other minor causes of AV block

Answer 2

Other causes- 
hyperkalemia
infiltrative malignancies (rare)
neonatal Lupus
severe hypo or hyperthyroidism
trauma
degenerative neuromuscular disease (lead to scarring and fibrosis of conduction system- myotonic dystrophy)

Question 3

what is the definition of AV block

Answer 3

AV Block is defined as a delay or interruption in the transmission of an impulse from the atria to the ventricles due to an anatomic or functional impairment in the conduction system.

Question 4

what drugs cause heart block

Answer 4

verapamil, diltiazem (CCB) - these drugs decrease LV function (they are negative ionotropes and chronotropes)

Digitalis

beta blockers- especially cause HB if you use with CCB.

Amiodarone- for atrial dysrhythmias- 1/2 life of 50 days

Adenosine- 1/2 life is miliseconds. used for fast atrial reentry rhythms, such as PSVT (paroxsymal ventricular tachycardia)

Question 5

what are surgical interventions, treatments or procedures that cause heart block

Answer 5

Cardiac Surgery

Catheter ablation of arrhythmias

Transcatheter VSD closure

Alcohol Septal ablation for HOCM

TAVr (Transcatheter AV replacement)

Question 6

rheumatic fever can cause what?

Answer 6

mitral stenosis occurs

pulmonary HTN occurs