Dr. Usman's Cardiology Notes

 👉 In practice, ablation is often considered when VT is drug-refractory, recurrent, or causing ICD shocks, provided the patient can safely undergo the procedure. How isoprenaline (isoproterenol) controls VT ? The way isoprenaline (isoproterenol) controls VT depends on the mechanism of arrhythmia. 1. Idiopathic VF / Brugada / Early repolarization syndrome These arrhythmias are triggered by phase-2 reentry or Purkinje PVCs. At slow heart rates, abnormal repolarization (J-wave accentuation, action potential heterogeneity) favors PVCs and VF. Isoprenaline (β-agonist) increases sympathetic tone → raises heart rate → shortens action potential duration and suppresses early afterdepolarizations. This reduces dispersion of repolarization and stabilizes the ventricular myocardium. Net effect: PVC suppression → VF/VT storm breaks. 2. General mechanism β-1 stimulation → increases HR and conduction → overrides pause-dependent triggers. β-2 stimulation → increases calcium influx → suppresses ph...

A 40 years old male diabetic with previous history of myocardial infarction and LVEF 35% presented with shortness of breath and chest pain. His functional capacity is poor due to underlying dyspnea on exertion. He was apprehensive, tachycardiac and maintaining his BP around 100/60 mmHg. ECG showed gross ST depression in precordial leads more than 2mm with non-progressive R waves. Trops were negative. Immediately on arrival to CCU he suddenly collapse and started gasping, monitor showed monomorphic VT with rate of 200bpm. He was resuscitated with 200Jshock and CPR for 5minutes. On revival, he was shifted to cath lab where coronary angiogram showed TVCAD a)       What is the reason for monomorphic VT b)       Would you consider ICD for this patient during his hospital stay c)       What additional workup is indicated before surgery d)       What is the mortality of CABG? Answers: a.  ...