Cardiology Facts 5


  • Early direct current (DC) shock defibrillation is most important for successful resuscitation of an adult patient with out-of-hospital cardiac arrest
  • One French unit (F), a measurement of catheter diameter, is equivalent to 0.33mm
  • Dual-chamber pacemaker for sinus node dysfunction+heart failure+dilated left ventricle with severe global LV  systolic dysfunction - decrease the percentage of RV pacing by pacemaker interrogation
  • ETT ST-segment depressions probability of diagnosing signicant coronary artery disease increases with normal baseline ECG without LBBB, LVH,WPW, digoxin effect 
  • STEMI, ostial occlusion of dominant RCA, bradycardia, hypotension, abnormal heart rate and blood pressure are likely a consequence of vagal stimulation. Dominant RCA supplies inferoposterior left ventricle where cardiac vagal afferent fibers are prominent
  • Shocks from ICD without any arrhythmias, most appropriate initial step is to place a “donut” magnet over ICD site
  • Exertional dyspnea, fatigue, sudden lightheadedness+cardiopulmonary exercise testing failure to reach 80% maximum predicted HR with exercise - chronotropic incompetence, which is one manifestation of sinus node dysfunction
  • CAD + LVEF below 35% + nonsustained VT - ICD is indicated if EP study shows inducible VT