Permanent pacing after transcatheter aortic valve implantation of a CoreValve prosthesis as determined by electrocardiographic and electrophysiological predictors: a single-centre experience.

AIM: The most frequent conduction complications with transcatheter aortic valve implantation (TAVI) are complete atrioventricular (AV) block and new bundle branch block (BB). The purpose of this study was to assess clinical, electrocardiographic, and electrophysiological predictors of conduction abnormalities in patients (pts) undergoing TAVI with the CoreValve prosthesis. The secondary end points were the long-term rhythm follow-up and the recovery of conduction. METHODS AND RESULTS: Forty-five consecutive pts with severe aortic stenosis, New York Heart Association II/III, and normal or slightly impaired left ventricular function who underwent CoreValve transcatheter implantation were randomized 2:1 to electrocardiographic and electrocardiographic plus electrophysiological evaluations. Pacemakers were implanted in pts with complete AV block. Follow-up was performed at 1, 6, 12, and 24 months. Conduction was affected in the total group of pts undergoing TAVI. The PR lengthened compared with the baseline but did not exceed the normal cut-off of 200 ms, and the QRS widened, basically due to new left bundle branch blocks (LBBBs). Within 1 month of follow-up, 10 pts (22%) developed complete AV block (9 peri-procedurally-20%) and 15 pts (33%) developed a new bundle BB, with LBBBs being the most common (14-31%). In the 30 pts who underwent an electrophysiological study, analysis showed that prolonged HV intervals were prognostic for pacemaker implantation. Follow-up in the total study group revealed that only 4 of the 10 (9%) initial implantations remained completely pacemaker dependent. CONCLUSION: Conduction was affected in all pts undergoing TAVI, but serious complications that required permanent pacing generally occurred in pts with pre-existing conduction abnormalities.

Safety of screening procedures with hand-held metal detectors among patients with implanted cardiac rhythm devices: a cross-sectional analysis.

BACKGROUND: Case reports suggest that the hand-held metal detectors used for security screening generate electromagnetic fields that may interfere with pacemaker and implantable cardioverter-defibrillator (ICD) function. OBJECTIVE: To assess changes in function of pacemakers and ICDs after exposure to hand-held metal detectors. DESIGN: Cross-sectional study. SETTING: Two medical centers in Europe. PATIENTS: 388 patients (209 with pacemakers and 179 with ICDs) presenting for routine follow-up of device function between September 2009 and December 2010. MEASUREMENTS: Abnormalities on electrocardiography suggestive of rhythm device malfunction (pacing inhibition, loss of capture, inappropriate mode switch, ventricular oversensing, and spontaneous reprogramming) after 30 seconds of exposure to 2 widely used hand-held metal detectors with a maximal electromagnetic flux density of 6.3 µT. RESULTS: No change in device function, including pacing or sensing abnormalities or device reprogramming, was observed in any patient. LIMITATIONS: The study included a convenience sample of patients, and the number of different device models tested was small. Testing was conducted in 2 clinic settings. CONCLUSION: Hand-held metal detectors did not affect the function of pacemakers or ICDs in this sample. The use of hand-held metal detectors for security screening is probably safe for patients with pacemakers and ICDs, but these findings require confirmation. PRIMARY FUNDING SOURCE: None.

Acute and long term results of unprotected left main stenting using drug eluting stents.

BACKGROUND: Most available data indicates that stenting for unprotected left main coronary artery disease (ULMCA) with drug-eluting stents (DES) is safe and effective. At present, surgery is considered the gold standard for optimal revascularization. The aim of this study was to evaluate the immediate and long term outcome of patients with ULMCA stenosis who underwent percutaneous coronary intervention (PCI) with DES implantation in a single center. METHODS: Coronary stents were implanted into ULMCA in 72 patients. Patients with a de novo ≥ 50% diameter stenosis, or ≤ 4.0 mm(2) on intravascular ultrasound measurement of left main coronary artery were treated using 1.6 ± 1.2 DES per patient. ULM stenting was performed when coronary artery bypass grafting was considered at high surgical risk (mean EuroSCORE 7.1) and/or surgery was refused despite their physician's recommendation. Patients enrolled in the study underwent clinical evaluation one, six and 12 months after the procedure, and then annually. Coronary angiography was routinely performed at nine to 12 months from the index procedure and/or was clinically driven at any time. Acute and long term main adverse cardiac events (MACE) were assessed: cardiac death, myocardial infarction and additional target lesion or non-target lesion revascularization (TLR). RESULTS: Angiographic and clinical success of PCI was 100%. Complete revascularization was performed in all patients. Mean follow-up duration was 2.5 years ± 10 months with 3% mortality in the first 12 months and total MACEs in 30.6%. During follow-up, death occurred in four (5.5%) patients. Angiographic follow-up was performed in 59 (82%) patients and TLR occurred in 18.05% of treated lesions. One possible stent thrombosis was documented. CONCLUSIONS: Considering the high surgical risk present in most of our patients, ULM stenting is feasible and safe with excellent immediate and mid-term results. Long term results seem to be encouraging, showing limited mortality and the total absence of definite or probable thrombosis.

Disorders of the autonomic nervous system in patients with Brugada syndrome: a pilot study.

INTRODUCTION: The aim of this study was to examine autonomic disorders in patients with Brugada syndrome by performing a cardiac sympathetic innervation evaluation, a head-up tilt-test (HUT) and heart rate variability (HRV) analysis. METHODS AND RESULTS: We enrolled 20 patients with Brugada syndrome (mean age 42.5 +/- 8.8 years), 9 with spontaneous and 11 with an induced type 1 electrocardiogram (ECG) in the setting of symptoms and 20 age-matched controls. All subjects underwent a HUT with parallel measurements of plasma catecholamines and cortisol, a (123)I-metaiodobenzylguanidine single photon emission tomography, and HRV evaluation. Ten control subjects participated in the innervation portion of the study. The tilt-test with clomipramine challenge was positive in 15 of 20 (75%) patients (7 spontaneous, 8 induced) and in 1 in controls (P < 0.01). A sympathoadrenal imbalance was shown in positive tests. The pattern of innervation in all groups was heterogenic and similar to controls with a trend towards lower measurements in patients with a spontaneous type 1 ECG and a positive HUT. HRV analysis did not reveal any significant differences during day and night. Four patients (20%) had sustained ventricular arrhythmias during a follow-up of 31.1 +/- 8.6 months, but no correlations with innervation or response to tilting were found. CONCLUSION: A high susceptibility to vasovagal syncope was observed in patients with Brugada syndrome, which could be disease-related symptoms. Conversely, sympathetic innervation was observed to follow a physiological, heterogenic pattern; however, these factors did not have prognostic value for life-threatening arrhythmias.

The Windkessel model revisited: a qualitative analysis of the circulatory system.

In this paper, we derive a comprehensive computational model to estimate the arterial pressure and the cardiac output of humans, by refining and adapting the well-established equations of the Windkessel theory. The model inputs are based on patient specific factors such as age, sex, smoking and fitness habits as well as the use of specific drugs. The model's outputs correlate very strongly with physiological observations, with a low error of approximately 5% for the arterial pressure.

Contribution of electroanatomical mapping to the diagnosis of arrhythmogenic right ventricular cardiomyopathy in a patient with sustained ventricular tachycardia.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary cardiomyopathy, characterized mainly by anatomic and functional defects of the right ventricle. In many cases its diagnosis is quite difficult in spite of the existence of defined diagnostic criteria for the disease. We describe an interesting case of a patient with sustained ventricular tachycardia derived from the right ventricular outflow tract, in whom the diagnosis of ARVC was made with the contribution of electrophysiologic study and electroanatomical mapping, as the use of all other diagnostic tests and laboratory methods had left many unanswered questions. Based on our case, but also on other studies and case reports in the literature, we conclude that electroanatomical mapping is useful for the documentation of the diagnosis of ARVC, whenever this is not clear from the use of available diagnostic tests according to the defined criteria of the disease.