Tachycardia-induced cardiomyopathy long after a pacemaker implantation for the treatment of unusual 2:1 atrioventricular block: What is the mechanism? (original) (raw)
Related papers
Türk Kardiyoloji Derneği arşivi : Türk Kardiyoloji Derneğinin yayın organıdır, 2009
Concealed conduction commonly occurs when a retrogradely conducted interpolated ectopic impulse enters the atrioventricular (AV) node; thus, the next sinus beat is not conducted to the ventricle or conducted with a prolonged PR interval because of increased refractoriness of AV conduction system. A 67-year-old man had complaints of exertional fatigue and palpitations at rest. His blood pressure was 110/70 mmHg and heart rate was 78 beats/min. Auscultation revealed a mild systolic murmur at the apex and an irregular rhythm. His electrocardiogram was normal, except for the presence of frequent premature ventricular complexes (PVC) of right bundle branch block morphology. Echocardiographic examination showed only grade-1 mitral regurgitation. Further evaluation with 24-h Holter monitoring showed frequent interpolated PVCs in bigeminal rhythm. Progressive prolongation of the PR interval was observed after each PVC, which ended with Mobitz type I AV block. The patient was treated with me...
International Journal of Cardiology, 2013
Introduction: Ventriculoatrial (VA) conduction and related pacemaker-mediated tachyarrhythmias (PMT) have not been systematically investigated in a large cohort of patients implanted for symptomatic atrioventricular (AV) block. Methods and results: Two hundred fifty consecutive patients (71 ± 14 years, 63% male) implanted for symptomatic second-or third-degree AV block were screened for retrograde VA conduction and related PMTs including endless loop tachycardia (ELT) and repetitive nonreentrant VA synchrony (RNRVAS). After a mean post-implantation period of 38 ± 12 months, AV block was persistent in 137 (55%) and variable in 113 (45%) patients. Retrograde 1:1 conduction was present in 76 patients (30%) with a mean VA conduction time of 258 ± 65 ms. The incidence of VA conduction varied considerably according to the presence and type of anterograde conduction block. Retrograde conduction was present in 24 of 137 patients (18%) with persistent AV block. Fifteen of the 76 patients (20%) with VA conduction had ≥1 documented PMT. The recorded arrhythmias were ELT in 11 and RNRVAS in 4 patients. VA conduction time was significantly longer in patients with than without PMT (297 ± 64 vs. 249 ± 62 ms, resp., P b 0.01). None of the patients without VA conduction had documented PMTs. Conclusions: Retrograde VA conduction and related PMTs are not uncommon in patients implanted for symptomatic AV block. Testing for retrograde conduction should therefore be performed in all patients with AV block in order to optimize device programming and prevent PMTs.
Tachycardia after pacemaker implantation in a patient with complete atrioventricular block
Europace, 2007
The atrioventricular (AV) node allows ante-and retrograde conduction between atria and ventricles. It is commonly assumed that these AV nodal conduction properties go hand in hand. However, ante-and retrograde AV conduction can be completely independent from each other in individual patients. We report about a patient with permanent AV block III8 requiring implantation of a pacemaker. As soon as a dual-chamber device was connected to the implanted leads, a tachycardia started at the maximum tracking rate, which was subsequently reprogrammed from 120 to 170 bpm. Non-invasive electrophysiologic testing showed that this patient demonstrated 1:1 ventriculoatrial (VA) conduction up to 170 bpm leading to endless loop tachycardia (ELT) while the antegrade AV block III8 persisted. This case impressively illustrates that one has to take into account that patients with antegrade AV block III8 may still have a high VA conduction capacity leading to ELT. Dual-chamber devices therefore have to be programmed accordingly, activating dedicated reactions after ventricular premature beats and automatic ELT detection and termination algorithms.
Journal of Cardiovascular Electrophysiology, 2018
A 49-year-old man with a complex congenital heart disease (comprising dextrocardia with situs solitus, atrial septal defect, ventricular septal defect, severe pulmonary stenosis and D-transposition of the great arteries surgically repaired by means of the Rastelli procedure at the age of 22 years) underwent single-chamber defibrillator (ICD) implantation for primary prevention of sudden cardiac death due to severe systolic dysfunction of the systemic ventricle. The right ventricular lead (RV; Durata 7120, St. Jude Medical TM, Sylmar, CA, US) was implanted using a conventional transvenous approach. Two years later the patient developed heart failure symptoms and the ECG showed sinus rhythm with first degree AV block and left bundle branch block QRS morphology. Therefore, upgrade to cardiac resynchronization therapy (Unify 3235-40Q CRT-D, St Jude Medical TM, Sylmar, CA, US) was performed in 2012. Two epicardial leads were surgically implanted in the left atrium (LA; Miopore 511212, Greatbatch medical TM) and left ventricle (LV; 6071, Medtronic TM, Minneapolis, US). The X-ray lead positioning is shown in Figures 1A and 1B. The patient was followed by remote monitoring. Pacing and sensing parameters were stable (R wave 5.5 mV, RV threshold 1.0V at 0.5 ms; P wave 3.1 mV, LA threshold 0.75V at 0.5 ms; LV threshold: 1.75V at 0.5 ms) and no arrhythmic episodes were documented during the follow-up. The real time EGM showed a significant far-field of the ventricular signal in the atrial channel, as consequence of proximity of epicardial lead. The ventricular far-field falls in the blanking period,