Bidirectional ventricular tachycardia with myocardial infarction: a case report with insight on mechanism and treatment

Unusual Tachycardia After Cocaine Use

This case report presents the electrocardiogram findings of a patient in their 20s with severe midsternal chest pain of several hours’ duration after cocaine use.

Bidirectional Ventricular Tachycardia in Acute Multivessel Myocardial Infarction

Bidirectional ventricular tachycardia (BVT) is a rare and unusual ventricular dysrhythmia that is characterized by a beat-to-beat alternation of the QRS axis. This can sometimes manifest as alternating left and right bundle branch blocks. To the best of our knowledge, there are two previous cases of BVT in the setting of type I myocardial infarction. Our case would be the third and showed a subtle change in the anterior-posterior axis that can be seen in lead V2. The coronary angiography of our patient demonstrated severe multivessel coronary artery disease with complete total occlusion of the proximal dominant right coronary artery, 100% in-stent restenosis of the ostial left circumflex, 40% stenosis of left main, and 90% stenosis of mid left anterior descending artery (LAD). The BVT resolved after two amiodarone boluses followed by a drip. We attempted to transition to oral mexiletine, however, the patient was unable to tolerate the medication due to intractable nausea and vomiting. The patient subsequently underwent high risk coronary artery bypass graft surgery with no further episodes of BVT following revascularization and was discharged after six weeks of hospitalization. Although rare, type I myocardial infarction is an important differential diagnosis of BVT. 

Bidirectional Ventricular Tachycardia: Challenges and Solutions

Bidirectional ventricular tachycardia (BiVT) is a rare form of ventricular tachycardia that manifests on surface electrocardiogram by dual QRS morphologies alternating on a beat-to-beat basis. It was first reported in the 1920s as a complication of digoxin, and since then, it has been reported in other conditions including fulminant myocarditis, sarcoidosis, catecholaminergic polymorphic ventricular tachycardia, and Andersen-Tawil syndrome. The mechanism for BiVT is not as well known as other forms of ventricular tachycardia but appears to include typical mechanisms including triggered activity from afterdepolarizations, abnormal automaticity, or reentry. This review will go beyond the definition, surface electrocardiogram, mechanisms, causes, and treatment of BiVT as per our current understanding.

Polymorphic Wide QRS Complex Tachycardia: Differential Diagnosis

Polymorphic wide QRS complex tachycardia is defined as a tachyarrhythmia showing variable and frequently alternating morphologies of the QRS complex with irregular R-R intervals. It may present with a specific and reproducible pattern including torsade de pointes and bidirectional ventricular tachycardia or with a nonspecific and very irregular pattern, different from ventricular fibrillation. Polymorphic ventricular tachycardia is a challenging diagnosis and is associated with a high risk for sudden cardiac death. Although rare, preexcited atrial fibrillation over multiple accessory pathways can also generate a polymorphic wide QRS complex tachycardia mimicking polymorphic ventricular tachycardia.

Left Ventricular Aneurysm Presenting as Bidirectional Ventricular Tachycardia

Background

Bidirectional ventricular tachycardia is a rare form of ventricular arrhythmia, characterized by a changing of the mean QRS axis of 180 degrees. Digitalis toxicity is the most common cause of bidirectional ventricular tachycardia; other causes include myocarditis, aconite toxicity, metastatic cardiac tumor, myocardial infarction, and cardiac channelopathies.

Case Report

A 73-year-old male with hypertension and a pacemaker implanted for sick sinus syndrome presented with a complaint of substernal chest pressure for several days. He also stated he had had an episode of near syncope. The patient's physical examination was unremarkable; however, electrocardiogram demonstrated sustained bidirectional ventricular tachycardia. Echocardiogram showed severe anterior wall hypokinesis and an estimated ejection fraction of 35%, as well as an apical ventricular aneurysm. Electrophysiology study showed that the apical ventricular aneurysm was the site of the bidirectional arrhythmia. The patient was successfully treated with ventricular tachycardia ablation.

Conclusion

This case is a unique example of a patient with bidirectional ventricular tachycardia originating from an apical left ventricular aneurysm that was treated successfully by ablation.

Accelerated idioventricular rhythm degenerating into bidirectional ventricular tachycardia following acute myocardial infarction

Bidirectional ventricular tachycardia (BVT) is a rare ventricular tachyarrhythmia. It is usually regular, demonstrating a beat-to-beat alternation in the QRS frontal axis that varies between -20° to -30° and +110°. The tachycardia rate is typically between 140 and 180 beats/min and the QRS is relatively narrow, with a duration of 120 to 150 ms. The etiology of published BVT cases is most commonly digitalis toxicity and, rarely, herbal aconitine poisoning, hypokalemic periodic paralysis, catecholaminergic polymorphic ventricular tachycardia (CPVT), myocarditis, and Andersen-Tawil syndrome. We report a case of accelerated idioventricular rhythm (AIVR) degenerating into BVT following acute myocardial infarction, and briefly discuss the proposed mechanisms underlying BVT.