DIgitalis

Question 1

A-flutter

Answer 1

• macro-re-entrant arrhythmia that circulates in counterclockwise manner in RA
• accompanied by AV block, sawtooth F waves on EKG, best in leads II and V1
• c/w CAD or mitral valve dz, PE, hyperthyroid, cardiac trauma, myocarditis
• Atrial rates 250-350, v rates >150
• regular atrial rhythm, v rhythm regular if fixed AV block, irregular if variable (can be 2:1 to 8:1)

Question 2

treatment aflutter

Answer 2

• pharmacologic

- synchronized cardioversion (only after risks of thromboembolic events have been assessed by cardiologist

Question 3

pharmacologic therapy

Answer 3

• first line–beta blockers (esmolol), propranolol–slow AV conduction, control ventricular response
• 2nd line CCB-verapamil 5-10 mg, diltiazem

Question 4

synchronized cardioversion

Answer 4

• xs rapid ventricular rates, hemodynamic instability

- start 100J, increasing to 360 J

Question 5

other drugs

Answer 5

• Class III antiarrhythmics–ibutilide in new onset AF–need to monitor 12 hrs for torsades
• amio 150 over 10 min
• procainamide

Question 6

Afib

Answer 6

• rapid atrial focus with no P waves
• irregularly irregular
• loss of atrial kick–impair CO
• atrial thrombi–inc pulm/systemic embolization
• atrial rates 350-500, v rates 60-170
• no p waves
• more likely to assoc with cardiac disease, CAD/mitral valve disease, PE, hyptherthyroid, cardiac trauma, myocarditis

Question 7

cardiac surgery

Answer 7

• AF 10% all noncardiac surgery, 30% thoracic, 15-45% cardiac surgeries
• inc morbidity, mortality, hospital stays
• preop beta blockers, periop amio/sotalol/CCB/Mg can help

Question 8

pharma therapy

Answer 8

• control ventricular response
• beta blockers (esmolol), CCB (diltiazem)
• ibutilide less effective in restoring sinus rhythm, less often used in afib

Question 9

synchronized cardioversion

Answer 9

• biphasic cardioversion for afib with hemodynamic instability
• inc risk of thromboembolism, if Afib>48 hrs, need anticoagulation for 3-4 weeks before cardioverting

Question 10

chronic afib therapy

Answer 10

• anticoagulation-coumadin, dabigatran
• V-contorl-b blockers, CCB, digitalis, catheter ablation of AV junction, pacer
• paroxysmal afib–radiofrequency ablation

Question 11

therapy for no sig CAD/LV dysfunc

Answer 11

-Class Ic antiarrhythmic–flecainide, propafenone

Question 12

Digitalis formulation

Answer 12

-digoxin, digitoxin, oubain–cardiac glycosides

Question 13

indication

Answer 13

• CHF and in setting of SVTs like afib, to slow ventricular response
• inhibits Na-K ATPase–inc intracellular calcium and prolonged AV conductance, positive intoropy, inc muscle automaticity