Idiopathic accelerated idioventricular rhythm or ventricular tachycardia originating from the right bundle branch: unusual type of ventricular arrhythmia.
BACKGROUND
Accelerated idioventricular rhythm (AIVR) or ventricular tachycardia (VT) originating from the right bundle branch (RBB) is rare and published clinical data on such arrhythmia are scarce. In this study, we will describe the clinical manifestations, diagnosis, and management of a cohort of patients with this novel arrhythmia.


RESULTS
Eight patients (5 men; median age, 25 years) with RBB-AIVR/VT were consecutively enrolled in the study. Pharmacological testing, exercise treadmill testing, electrophysiological study, and catheter ablation were performed in the study patients, and ECG features were characterized. All RBB-AIVR/VTs were of typical left bundle-branch block morphology with atrioventricular dissociation. The arrhythmias, which demonstrated chronotropic variability, were often isorhythmic with sinus rhythm and were accelerated by physical exercise, stress, and intravenous isoprenaline infusion. The rate of RBB-AIVR/VT varied from 45 to 200 beats per minute. Two patients experienced syncope, and 3 had impaired left ventricular function. Metoprolol was proven to be the most effective drug to decelerate the arrhythmia rate and relieve symptoms. Electrophysiology study was performed in 5 patients and the earliest activation with a sharp RBB potential was localized in the mid or distal RBB area. Catheter ablation terminated the arrhythmia with subsequent RBB block morphology during sinus rhythm. During follow-up, patients' symptoms were controlled with normalization of left ventricular function either on metoprolol or by catheter ablation.


CONCLUSIONS
RBB-AIVR/VT is an unusual type of ventricular arrhythmia. It can result in significant symptoms and depressed ventricular function and can be successfully treated with catheter ablation.
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.). chenminglong@njmu.edu.cn.
Minglong
M
Chen
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Kai
K
Gu
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Bing
B
Yang
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Hongwu
H
Chen
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Weizhu
W
Ju
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Fengxiang
F
Zhang
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Gang
G
Yang
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Mingfang
M
Li
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Xinzheng
X
Lu
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Kejiang
K
Cao
From the Division of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China (M.C., K.G., B.Y., H.C., W.J., F.Z., G.Y., M.L., X.L., K.C.); and II Medizinische Abteilung, Allgemeines Krankenhaus St. Georg, Hamburg, Germany (F.O.).
Feifan
F
Ouyang
D000200:Action Potentials; D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D002036:Bundle of His / Q000503:physiopathology* / Q000601:surgery; D002037:Bundle-Branch Block / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left; D055815:Young Adult
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents
accelerated idioventricular rhythm; bundle-branch block; catheter ablation; electrophysiology; ventricular tachycardia