Biomedical subjects
Publications and source records attributed to Rafael Peinado.
Class I antiarrhythmic drug infusion has been established as the standard test to unmask Brugada syndrome. This report presents two patients with Brugada syndrome with positive flecainide response which was not reproducible in a subsequent test.
Management of patients with incessant monomorphic ventricular tachycardia is challenging. We report on 2 patients who had incessant ventricular tachycardia despite emergency treatment with antiarrhythmic drugs and repeated electrical cardioversions. In both cases, the arrhythmia was acutely terminated with intracoronary administration of radiographic contrast media, allowing hemodynamic stabilization. No tachycardia recurrences occurred.
We report of a patient in whom the presence of a left ventricular accessory pathway plus enhanced AV nodal conduction led to a more physiological ventricular activation sequence than that observed after ablation of the accessory pathway in a patient with baseline left bundle branch block and concealed intra-QRS pre-excitation.
BACKGROUND: The purpose of this investigation is to compare the efficacy of antitachycardia pacing (ATP) delivered via the right ventricular (RV) lead versus ATP delivered simultaneously via the right and left ventricular leads (biventricular [BiV]) in the termination of ventricular tachyarrhythmia (VT) in patients receiving cardiac resynchronization therapy (CRT) with ICD capabilities. METHODS AND RESULTS: The ADVANCE CRT is a prospective, multicenter, randomized, parallel trial evaluating RV versus BiV ATP in the termination of VT in CRT patients. The study will test the hypothesis that BiV ATP is superior to RV ATP in the termination of VT and fast VT. All patients with class I and IIa indications for an ICD implantation and CRT are included. The sample size has been estimated to 400 participants followed for 12 months to show a 10% benefit of BiV versus RV ATP. The efficacy of BiV ATP to terminate all VT presents the primary endpoint. The investigation is expected to be completed in 2007. CONCLUSIONS: The ADVANCE CRT trial is the first large randomized clinical investigation evaluating the efficacy of BiV ATP in patients under CRT and ICD therapy.
INTRODUCTION AND OBJECTIVE: We report the results for the Spanish Registry on Implantable Cardioverter Defibrillators (ICD) (year 2005), developed by the Working Group on ICD of the Spanish Society of Cardiology. METHODS: Data were collected (prospectively in 77% of implants) by single page form questionnaires transmitted after the procedure to the Spanish Society of Cardiology. Participation was voluntary. RESULTS: The number of implants sent to the Registry was 2050 and this represents 74.4% of the total ICDs implanted. The implantation rate per million was 46.5 and the estimated total implantation rate per million was 62.5. The proportion of first implants was 70.3%. The majority of patients were males, with a median age of 65 years, severe or moderate to severe left ventricular dysfunction and in functional class II or I. Ischemic heart disease was the more frequent underlying heart disease followed by dilated cardiomyopathy. The main reason for ICD indication was secondary prevention related to sustained monomorphic ventricular tachycardia or aborted sudden cardiac death. A significant number of prophylactic indications were done, specially in non ischemic heart disease. The proportion of ICD implanted at the electrophysiology laboratory by cardiac electrophysiologist continues increasing. There was an increase in the number of ICD plus cardiac resynchronization therapy, that represent a 23.6% of the implants. The incidence of complications during the implant was very low. CONCLUSIONS: The National Registry on ICD, with a participation rate greater than in previous years, provides a representative sample of the ICD implants performed at our country.
The aim of this study was to identify mutations in the cardiac heavy-chain beta-myosin gene (MYH7b) in a group of Spanish patients with hypertrophic cardiomyopathy. The study included 36 families with at least one member who had hypertrophic cardiomyopathy. DNA from exons 3 to 24 of the MYH7b gene was sequenced. Two mutations were identified: Arg858Cys and Met515Val. They occurred in two families, one of which was of Moroccan origin. This corresponds to a MYH7b gene mutation frequency of less than 5%. In contrast to findings in other Caucasian populations, MYH7b gene mutation occurred infrequently in this group of Spanish families with hypertrophic cardiomyopathy.
AIMS: We sought to determine the incidence, mechanisms, and time to syncope recurrence in patients with spontaneous syncopal monomorphic ventricular tachycardia (SyMVT) treated with an implantable cardiac defibrillator (ICD). METHODS AND RESULTS: Incidence and causes of syncope following ICD implantation in consecutive patients (n=26) with spontaneous SyMVT were compared with those found in consecutive patients (n=50) with spontaneous non-syncopal monomorphic ventricular tachycardia (NSyMVT). Patients with SyMVT had a higher incidence of syncope (46% patients) than those with NSyMVT (2% patients) at 31+/-21 and 34+/-23 months follow-up, respectively (hazard ratio, 0.19; 95% confidence interval, 0.04-0.42; P=0.0001). Among the former, four patients (15%) had non-arrhythmic syncope and eight patients had arrhythmic syncope (31%), which was associated with either ICD proarrhythmia (seven episodes of VT acceleration or VF degeneration by ATP or low/high-energy shocks in three patients) or spontaneous VT and VF (five episodes in five patients). Median time to the first arrhythmic syncope was 376 days. Arrhythmic syncope presented after a first non-syncopal VT recurrence in six patients (75%). CONCLUSION: Syncope following ICD implantation is common in patients with SyMVT in contrast to patients with NSyMVT. Late syncope presentation supports reassessment of driving restrictions in this setting.
The mechanism by which atrial fibrillation is initiated in patients with accessory pathways is not fully understood. Retrograde conduction of ventricular premature beats to the atrium, causing the arrhythmia, is a very rare cause. We report a patient with Wolff-Parkinson-White syndrome (WPW), without previous tachycardias, who presented multiple episodes of paroxysmal atrial fibrillation after having a myocardial infarction. During the electrophysiological (EP) study the patient presented two spontaneous episodes of atrial fibrillation initiated by ventricular premature beats conducted to the atria through the accessory pathway. After successful catheter ablation of the accessory pathway the patient did not present arrhythmia recurrences.
INTRODUCTION: Reentry within a major thoracic vein has been suggested as a cause of atrial arrhythmias. However, little is known about these potential reentrant circuits. METHODS AND RESULTS: Atypical atrial flutter was induced and mapped in 67 out of 225 atrial flutter ablation procedures. Reentry around the superior vena cava (SVC) was suspected in three patients. The suspected SVC flutter was induced and terminated by pacing in all patients. Fusion was demonstrated during flutter entrainment by subeustachian isthmus pacing in all of them. The postpacing interval following entrainment by pacing from different sites of the right atrium (RA) or coronary sinus was longer than the flutter cycle length. Macroreentry within the SVC was demonstrated both by sequential activation and a postpacing interval matching the flutter cycle length when pacing from different sites around the SVC in all patients. Atrial-venous-atrial electrogram sequence was demonstrated following flutter entrainment by atrial pacing. Flutter was terminated by an electrical stimulus delivered to the SVC, which was not propagated to the trabeculated RA, in one patient, and linear radiofrequency application from the distal SVC to the posterior wall of the RA, or to the superoseptal portion of the crista terminalis, in the other two. CONCLUSION: Macroreentry within the SVC is a distinctive mechanism responsible for rapid atrial activation, which is different from other reported flutter mechanisms, such as upper loop reentry. SVC longitudinal radiofrequency application can eliminate the arrhythmia without the need for complete electrical disconnection of the vein.
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OBJECTIVE: To report the 2002-2004 findings of the Spanish National Implantable Cardioverter-Defibrillator (ICD) Registry, established by the Spanish Society of Cardiology Working Group on Implantable Cardioverter-Defibrillators. MATERIAL AND METHOD: Data were collected prospectively after implantation using a single-page questionnaire returned to the Spanish Society of Cardiology. Participation was voluntary. RESULTS: The registry received reports on 925, 1,046 and 1414 implants, respectively, in the years 2002, 2003 and 2004. These figures represent 63%, 59% and 67.5%, respectively, of the total number of ICDs implanted. The reported implantation rates were 22, 24 and 33 per million, respectively, and the estimated total implantation rates were 35, 41 and 49, per million, respectively. The number of device replacements increased from 20% to 30% between 2002 and 2004. The majority of patients were male, their median age was 66 years, they had severe or moderate left ventricular dysfunction, and they were in functional class I or II. The most common underlying heart disease was ischemic heart disease. The main indications for an ICD were sustained monomorphic ventricular tachycardia and aborted sudden cardiac death, though the number of prophylactic indications has increased. Most ICDs were implanted in an electrophysiology laboratory by a cardiac electrophysiologist. The implantation rates of dual-chamber ICDs and ICDs with cardiac resynchronization therapy were approximately 30% and 15%, respectively. Very few complications occurred during implantation. CONCLUSIONS: The Spanish National ICD Registry contains a representative sample of ICD implantations performed in the country. The registry is one of the largest reported.
Principal components analysis to examine the effect of blending (viz. the mixing and transfer of wine between cask rows in a "criaderas and solera" system) on metabolic activity in flor yeasts during biological aging of sherry dry wines was carried out. The variables used in the analysis were the wine compounds most deeply involved in the flor yeast metabolism, namely ethanol, acetaldehyde, glycerol, acetic acid, and l-proline. The greatest blending effect was found to be on the third and second "criadera", which are the stages where the yeasts show a high metabolic activity. The stages holding the oldest wine (viz. the first criadera and the solera) exhibited no differences before and after blending; therefore, the yeasts have a decreased biological activity in them and physical-chemical aging processes seemingly prevail over it.
INTRODUCTION: The ablation of ventricular tachycardia is limited by a number of factors that reduce the effectiveness of this intervention in patients with structural heart disease compared to other types of arrhythmia. Recent years have seen the development of several nonfluoroscopic navigation techniques that facilitate the mapping of complex arrhythmogenic substrates. One such technique, the LocaLisa system, has not previously been tested for the ablation of ventricular tachycardia. PATIENTS AND METHOD: A total of 32 patients with structural heart disease were treated at our center with ablation for sustained ventricular tachycardia. In 10 patients the LocaLisa system was used to visualize the catheters during the procedure. We compared the results in the LocaLisa group with those in a control group of 22 patients treated with conventional fluoroscopy-guided ablation. RESULTS: The success rate of ablation was 75% (9/12 procedures) in the LocaLisa group and 68% (17/25 procedures) in the control group (P=NS). In the LocaLisa group, mean total duration of the procedure (243 +/- 84), duration of ablation (86 +/- 56) and fluoroscopy time (46 +/- 19) did not differ significantly from those in the control group (244 +/- 72 min, 79 +/- 58 min, and 43 +/- 27 min, respectively). In the LocaLisa group the trend toward greater hemodynamic intolerance in ventricular tachycardia approached significance (42% in the LocaLisa group vs 24% in the control group, P=.05) and the number of mapping procedures performed during sinus rhythm was significantly higher in the former (33% in the LocaLisa group vs 4% in the control group, P=.03). With the LocaLisa system it was possible to locate and reposition the ablation catheter accurately at the target endocardial sites, as confirmed by electrographic recordings and fluoroscopic verification. CONCLUSIONS: The LocaLisa system helps to delineate the reentry circuit and facilitates accurate catheter repositioning in patients with structural heart disease and ventricular tachycardia.
Brugada syndrome is a clinical and electrocardiographic entity characterized by ST segment elevation in the right precordial ECG leads and sudden death or syncope secondary to malignant ventricular arrhythmia, and has a high recurrence rate. We report a patient with this syndrome who had received an automatic implantable defibrillator, who presented with multiple appropriate discharges because of recurrent episodes of ventricular fibrillation. All episodes were started by a premature ventricular beat of the same morphology and coupling interval. Endovenous procainamide administration, paradoxically, was effective in preventing new episodes. The beneficial antiarrhythmic effect of procainamide in this patient is discussed.
This report describes a 28-year-old pregnant woman with mitral valve prolapse and sudden cardiac death due to a ventricular fibrillation who underwent an ICD implantation guided by tranesophageal echocardiography.
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Explore the source record for details and available documents.