Cardionerds: A Cardiology Podcast

410. Case Report: A Curious Case of Refractory Ventricular Tachycardia – Rutgers-Robert Wood Johnson
CardioNerds (Dr. Colin Blumenthal and Dr. Saahil Jumkhawala) join Dr. Rohan Ganti, Dr. Nikita Mishra, and Dr. Jorge Naranjo from the Rutgers – Robert Wood Johnson program for a college basketball game, as the buzz around campus is high. They discuss the following case involving a patient with ventricular tachycardia:
The case involves a 61-year-old man with a medical history of hypothyroidism, hypertension, hyperlipidemia, seizure disorder on anti-epileptic medications, and major depressive disorder, who presented to the ER following an out-of-hospital cardiac arrest. During hospitalization, he experienced refractory polymorphic ventricular tachycardia (VT), requiring 18 defibrillation shocks. Further evaluation revealed non-obstructive hypertrophic cardiomyopathy (HCM). We review the initial management of electrical storm, special ECG considerations, diagnostic approaches once ischemia has been excluded, medications implicated in polymorphic VT, the role of multi-modality imaging in diagnosing hypertrophic cardiomyopathy, and risk stratification for implantable cardioverter-defibrillator (ICD) placement in patients with HCM.
Expert commentary is provided by Dr. Sabahat Bokhari. Episode audio was edited by CardioNerds Intern and student Dr. Pacey Wetstein.
“To study the phenomena of disease without books is to sail an uncharted sea, while to study books without patients is not to go to sea at all.” – Sir William Osler. CardioNerds thank the patients and their loved ones whose stories teach us the Art of Medicine and support our Mission to Democratize Cardiovascular Medicine.
US Cardiology Review is now the official journal of CardioNerds! Submit your manuscript here.
CardioNerds Case Reports Page
CardioNerds Episode Page
CardioNerds Academy
Cardionerds Healy Honor Roll
CardioNerds Journal Club
Subscribe to The Heartbeat Newsletter!
Check out CardioNerds SWAG!
Become a CardioNerds Patron!
- There is likely no benefit. An RCT published by Kudenchuk et al in 2016 in which patients who had a non-traumatic out-of-hospital cardiac arrest with shock-refractory VF or pulseless VT were randomly assigned to receive lidocaine, amiodarone, or saline placebo, in addition to standard care, showed that neither antiarrhythmic drug had a significantly higher rate of survival or favorable neurologic outcome compared to placebo6.
- The differential diagnosis for ventricular tachycardia includes myocardial ischemia, electrolyte derangements, medications that may cause QT prolongation, congenital long QT syndrome, Brugada syndrome, myocarditis, dilated cardiomyopathy, arrhythmic cardiomyopathies, and infiltrative or structural heart disease.
- Standard BLS and ACLS measures are first-line treatment for pulseless VT.
- For stable patients, the 2017 AHA/ACC/HRS0 guidelines list beta-blockers as first-line antiarrhythmic therapy because they have been shown to reduce mortality and suppress ventricular arrhythmias in structurally normal hearts3. Amiodarone is also listed, though its long-term effect on survival is unclear, with most studies showing no clear benefit over placebo 3. Lidocaine and mexiletine are also commonly used, but because they are less efficacious compared to amiodarone, they are usually used as combination therapy for refractory patients4. Multiple trials have demonstrated the efficacy of procainamide as an adjunct medication in patients with ongoing ventricular arrhythmias, despite amiodarone and lidocaine4. Quinidine has also been used for patients as a salvage therapy for patients with structural heart disease for recurrent ventricular arrhythmias despite antiarrhythmic drug treatment 4.
- Medications that are commonly associated with QT prolongation, therefore making patients more susceptible to developing VT, include Class I and Class III antiarrhythmics; fluoroquinolone and macrolide antibiotics, as well as antifungals; tricyclic antidepressants as well as certain SSRI’s and SNRI’s; and antipsychotics, among others5.
- Multimodal imaging, specifically cardiac MRI, is useful for reaching a diagnosis in patients with PMVT due to improved myocardial tissue characterization.
- Improved definition of the myocardium allows for the detection of structural abnormalities that may not be as easily visualized on TTE, such as LV non-compaction, now called excessive trabeculation of the left ventricle, and to more accurately measure left ventricular wall thickness, which is useful for diagnosing and risk stratifying patients with hypertrophic cardiomyopathy.
- Improved tissue characterization by measuring T1 relaxation time, T2 relaxation time, extracellular volume, and late gadolinium enhancement (LGE) pattern is also useful for diagnosing infiltrative disease. Certain LGE patterns are associated with different cardiac conditions and play a role in determining prognosis. For example, the detection of mid-wall LGE in patients with dilated cardiomyopathy portends an increased risk of adverse events.
- The updated 2024 HCM guidelines have outlined several risk factors for sudden cardiac death 1
- Other risk stratification markers include extensive LGE seen on cardiac MRI, apical aneurysm, and EF < 50% in patients without high-risk features 1
- The AHA HCM SCD Calculator can be used to risk stratify patients to assist with decision-making in ICD implantation in these patients2