Bruno Pereira Valdigem

Ablation of Ventricular Tachycardia in Chronic Chagasic Cardiomyopathy With Giant Basal Aneurysm Carto Sound, CT, and MRI Merge

Chronic chagasic cardiomyopathy (CCC) is a parasitic disease that presents with life-threatening ventricular arrhythmias, dilated cardiomyopathy, or sudden death. Basal and posterior wall motion abnormalities and left apical aneurysms are common. We present a report of a patient with CCC, sustained ventricular tachycardia (Vt) refractory to amiodarone 400 mg/day and carvedilol 25 mg/day BID with a giant left basal aneurysm as visualized by CT scan and intracardiac echocardiogram 3D reconstruction(Carto Sound). The patient underwent preprocedural CT scan data acquisition with 64-slice MDCT scanner Aquilion (Toshiba, Tochigi, Japan), and the images were used for 3D reconstruction with Cartomerge (Biosense Webster, Inc., Diamond Bar, CA). Images acquired using cardiac MRI confirmed the size and shape of …

The use of external event monitoring (web-loop) in the elucidation of symptoms associated with arrhythmias in a general population

Objective To correlate arrhythmic symptoms with the presence of significant arrhythmias through the external event monitoring (web-loop). Methods Between January and December 2011, the web-loop was connected to 112 patients (46% of them were women, mean age 52±21 years old). Specific arrhythmic symptoms were defined as palpitations, pre-syncope and syncope observed during the monitoring. Supraventricular tachycardia, atrial flutter or fibrillation, ventricular tachycardia, pauses greater than 2 seconds or advanced atrioventricular block were classified as significant arrhythmia. The association between symptoms and significant arrhythmias were analyzed. Results The web-loop recorded arrhythmic symptoms in 74 (66%) patients. Of these, in only 14 (19%) patients the association between symptoms and significant cardiac arrhythmia was detected. Moreover, significant arrhythmia was found in 11 (9.8%) asymptomatic patients. There was no association between presence of major symptoms and significant cardiac arrhythmia (OR=0.57, CI95%: 0.21-1.57; p=0.23). Conclusion We found no association between major symptoms and significant cardiac arrhythmia in patients submitted to event recorder monitoring. Event loop recorder was useful to elucidate cases of palpitations and syncope in symptomatic patients.

Successful Treatment of Ventricular Arrhythmia in Tetralogy of Fallot Repair Using Catheter Ablation

Tetralogy of Fallot (ToF) is one of the most prevalent congenital heart disease. Its surgical corrections may haemodinamically correct a disease, but the incisions may create scars that will originate ventricular arrhythmias. Even though life threatening arrhythmias are not common, some patients present unstable ventricular tachycardia (VT) of ectopic ventricular beats triggering heart failure and symptoms. We describe the treatment of a 16-years-old woman with late ToF repair and drug refractory Implantable cardioverter defibrillator (ICD) shocks. The patient underwent successful ablation of VT using X-ray and anatomic landmarks without the use of electroanatomical mapping. We were able to reduce drugs after one month of ablation and improve quality of life and symptoms. In this paper we describe the indications and perform a brief review of the key points for successful radiofrequency catheter ablation of VT in ToF patients.

Delayed Enhancement Assessment of Pulmonary Veins Using 3 Tesla Magnetic Resonance Imaging after Atrial Fibrillation Ablation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinical practice. Epidemiological data show that AF is associated with significant morbidity and mortality, resulting in high medical and hospital costs.1 The dismay generated by the modest impact of antiarrhythmic agents in the natural history of AF motivated the development of non-pharmacological methods aimed at curative treatment of this arrhythmia. In this context, over the past decade, catheter ablation with percutaneous techniques evolved considerably and has become a therapeutic option for selected patients with AF.2 Imaging methods, such as intracardiac echocardiography and electroanatomic mapping have been increasingly incorporated to increase the efficiency and safety of the method. The efficiency of ablation has been discussed in recent years to evidence factors that contribute to the recurrence rates of AF. Failure of the procedure is often attributed to resumed conduction between the pulmonary veins and the left atrium due to incomplete ablation of ectopic foci.3 Cardiac magnetic resonance (CMR) with delayed enhancement technique is a noninvasive imaging modality used to view areas of fibrosis. In the context of AF, it may be adapted to identify fibrosis induced by radiofrequency waves on the left atrial wall and in the pulmonary vein ostia after ablation of AF. The fibrotic regions present increased signal intensity on delayed enhancement due to the slow gadolinium washout in the injured tissue. In this scenario, initial studies suggest that CMR with evaluation of atrial fibrosis using the delayed enhancement technique can provide important information about the radiofrequency ablation sites, potentially identifying incomplete isolations and preexisting areas of atrial fibrosis that may result in a higher AF recurrence rate after the procedure.4

Early chronotropic response analysis in head up tilt table test

Syncope affects up to a quarter of population [1] and reflex etiology is themost prevalent. The head up tilt test (HUTT)was initially used to evaluate the responses to orthostatic stress in terms of research, and thereafter to investigate syncope [2]. Different protocols have been used showing sensitivity ranging from 30% to 50% and specificity around 90%.We studied the heart rate just after tilting to predict HUTT results in a population under investigation of unexplained syncope referred to our center from March 2005 to December 2009. Subjects were enrolled if there was previous unexplained syncope, no structural heart disease or use of drugs that interfere with cardiac chronotropism, any condition that affects the autonomic system such as diabetes or parkinsonism, and no contraindications to the test. All patients signed a consent form. Positive tests during the first 10 min were excluded from analysis. HUTT was performed after 6 h of fasting and an initial 10 minutes rest period was observed. Patients were tilted to 70°, up to 40 min during which HR and BP were monitored [3–5]. If necessary, 1.25 mg sublingual isosorbide was administered after 20 min. A drop in HR, BP or both followed by symptoms defined test positivity, according to VASIS classification. The HRstart was that in the end of the rest period. Likewise, the HRmax 10 min was the highest seen at monitor during this period. An area under the ROCwas calculated and used to determine the ability of the early chronotropic response-ECR to discriminate HUTT results. AUC greater than 0.7 mean good statistical relation, and not a performance by chance. We calculated sensitivity, specificity, positive likelihood ratio and negative likelihood ratiowith respective 95% CI for all possible cutoff points and determined the optimal using Youden index [6,7]. The quantitative variables with normal distribution were described as mean and standard deviation. The software SAS 9.2 was used in statistical analysis. We enrolled 390 patients with a mean age of 47 y old and 89 had positive HUTT— 39% hadmixed response, 20% vasodepressor, 16% cardioinhibitory and the remainder 25% a POTS or dysautonomic response [Table 1]. ECR was analyzed as the absolute HR increase and as a percentage increase. The absolute ECR in each pattern of response is shown in Table 2. In ROC analysis, a cutoff 21% increase in HRstart discriminated those with negative and positive HUTT with sensitivity of 66.11%, specificity of 75.28%, and AUC of 0.739 (95% CI: 0.692 to 0.782). An absolute cutoff of 15 bpm increase also discriminated groups with sensitivity of 71.43, specificity of 77.53, and AUC of 0.755 (95% CI: 0.709 to 0.796). Comparing both variables using Bootstrap analysis the difference was 0.01615, not statistically significant p=0.114 [Fig. 1]. Statistical analysis demonstrated that a 10% HRstart increase shows specificity of 93.2. A positive HUTT with smaller ECR is a very unusual finding. Spearman correlation coefficient (CI=95%) showed inverse relation between HUTT duration and ECR.We also studied ECR in different age and sex groups [Tables 3 and 4]. Previous studies showed different results on early hemodynamic parameters in HUTT [8–12]. Our paper has a comparatively greater population and we considered the HRstart that immediately before

Coronary heart disease patient with implantable cardioverter desfibrilator and electrical storm submitted to ventricular tachycardia ablation

Coronary heart disease patient with implantable cardioverter desfibrilator and electrical storm submitted to ventricular tachycardia ablation