Roberto Garcia-Civera

Mechanism of Syncope in Patients With Heart Disease and Negative Electrophysiologic Test

Background—In patients with syncope and structural heart disease, syncope is suspected to be attributable to a primary cardiac arrhythmia, but little is known of its mechanism when electrophysiologic study is unremarkable. Methods and Results—We applied an implantable loop recorder in 35 patients with overt heart disease at risk of ventricular arrhythmia, because these were patients with previous myocardial infarction or cardiomyopathy with depressed ejection fraction or nonsustained ventricular tachycardia in whom an electrophysiologic study was unremarkable. During a follow-up of 3 to 15 months, syncope recurred in 6 patients (17%) after a mean of 6±5 months; in 3 patients, the mechanism of syncope was bradycardia with long pauses (sudden-onset AV block in 2 cases and sinus arrest in 1 case); in 1 patient, there was stable sinus tachycardia; and in 2 patients, who had chronic atrial fibrillation, there was an increase in ventricular rate. A total of 23 episodes of presyncope were documented in 8 patients (23%): no rhythm variation or mild tachycardia in 12 cases, paroxysmal atrial fibrillation or atrial tachycardia in 10 cases, and sustained ventricular tachycardia in 1 case. No patient died during the study period nor suffered from injury attributable to syncopal relapse. Conclusions—The patients with unexplained syncope, structural heart disease, and negative electrophysiologic study had a favorable medium-term outcome with no case of death and a low recurrence rate of syncope without related injury. The mechanism of syncope was heterogeneous, and ventricular tachyarrhythmia was unlikely.

Diagnosis, management, and outcomes of patients with syncope and bundle branch block

Aims Although patients with syncope and bundle branch block (BBB) are at high risk of developing atrio-ventricular block, syncope may be due to other aetiologies. We performed a prospective, observational study of the clinical outcomes of patients with syncope and BBB following a systematic diagnostic approach. Methods and results Patients with ≥1 syncope in the last 6 months, with QRS duration ≥120 ms, were prospectively studied following a three-phase diagnostic strategy: Phase I, initial evaluation; Phase II, electrophysiological study (EPS); and Phase III, insertion of an implantable loop recorder (ILR). Overall, 323 patients (left ventricular ejection fraction 56 ± 12%) were studied. The aetiological diagnosis was established in 267 (82.7%) patients (102 at initial evaluation, 113 upon EPS, and 52 upon ILR) with the following aetiologies: bradyarrhythmia (202), carotid sinus syndrome (20), ventricular tachycardia (18), neurally mediated (9), orthostatic hypotension (4), drug-induced (3), secondary to cardiopulmonary disease (2), supraventricular tachycardia (1), bradycardia–tachycardia (1), and non-arrhythmic (7). A pacemaker was implanted in 220 (68.1%), an implantable cardioverter defibrillator in 19 (5.8%), and radiofrequency catheter ablation was performed in 3 patients. Twenty patients (6%) had died at an average follow-up of 19.2 ± 8.2 months. Conclusion In patients with syncope, BBB, and mean left ventricular ejection fraction of 56 ± 12%, a systematic diagnostic approach achieves a high rate of aetiological diagnosis and allows to select specific treatment.

Epidemiological characteristics and diagnostic approach in patients admitted to the emergency room for transient loss of consciousness: Group for Syncope Study in the Emergency Room (GESINUR) study

AIMSnTo assess the clinical presentation and acute management of patients with transient loss of consciousness (T-LOC) in the emergency department (ED).nnnMETHODS AND RESULTSnA multi-centre prospective observational study was carried out in 19 Spanish hospitals over 1 month. The patients included were > or =14 years old and were admitted to the ED because of an episode of T-LOC. Questionnaires and corresponding electrocardiograms (ECGs) were reviewed by a Steering Committee (SC) to unify diagnostic criteria, evaluate adherence to guidelines, and diagnose correctly the ECGs. We included 1419 patients (prevalence, 1.14%). ECG was performed in 1335 patients (94%) in the ED: 498 (37.3%) ECGs were classified as abnormal. The positive diagnostic yield ranged from 0% for the chest X-ray to 12% for the orthostatic test. In the ED, 1217 (86%) patients received a final diagnosis of syncope, whereas the remaining 202 (14%) were diagnosed of non-syncopal transient loss of consciousness (NST-LOC). After final review by the SC, 1080 patients (76%) were diagnosed of syncope, whereas 339 (24%) were diagnosed of NST-LOC (P < 0.001). Syncope was diagnosed correctly in 84% of patients. Only 25% of patients with T-LOC were admitted to hospitals.nnnCONCLUSIONnAdherence to clinical guidelines for syncope management was low; many diagnostic tests were performed with low diagnostic yield. Important differences were observed between syncope diagnoses at the ED and by SC decision.

Reproducibility of Electrocardiographic Findings in Patients With Suspected Reflex Neurally-Mediated Syncope

The reproducibility of electrocardiographic (ECG) recordings in syncopal recurrences and the diagnostic role of nonsyncopal arrhythmias are not well known. The objective of this study was to analyse the reproducibility of the ECG findings recorded with implantable loop recorders in 41 patients with suspected neurally-mediated syncope who were included in the International Study on Syncope of Uncertain Origin-2 study and that had > or =2 events recorded by implantable loop recorders. In these patients, the electrocardiogram obtained with the first documented syncope (index syncope) was compared with other recorded events. Twenty-two patients had > or =2 syncopes, and their electrocardiograms were reproducible in 21 (95%): 15 with sinus rhythm, 5 with asystole, and 1 with ventricular tachycardia; 1 had asystole at first syncope and sinus rhythm at recurrent syncope. In 32 patients with nonsyncopal episodes, an arrhythmia was documented in 9, and all of them had the same arrhythmia during the index syncope (100% reproducibility); conversely, when sinus rhythm was documented (23 patients) during nonsyncopal episodes, an arrhythmia was still documented in 6 during the index syncope (70% reproducibility; p = 0.0004). In conclusion, the ECG findings during the first syncope are highly reproducible in subsequent syncopes. The presence of an arrhythmia during nonsyncopal episodes is also highly predictive of the mechanism of syncope, but the presence of sinus rhythm does not rule out the possibility of arrhythmia during syncope. Therefore the finding of an arrhythmia during a nonsyncopal episode allows the etiologic diagnosis of syncope, and eventually to anticipate treatment, without waiting for syncope.

Ablation or conservative management of electrical storm due to monomorphic ventricular tachycardia: differences in outcome

AIMSnElectrical storm (ES) is a life-threatening condition that predicts bad prognosis. Treatment includes antiarrhythmic drugs (AAD) and catheter ablation (CA). The present study aims to retrospectively compare prognosis in terms of survival and ES recurrence in 52 consecutive patients experiencing a first ES episode.nnnMETHODS AND RESULTSnPatients were admitted from 1995 to 2011 and treated for ES by conservative therapy (pharmacological, 29 patients) or by CA (23 patients), according to the physicians preference and time of occurrence, i.e. conservative treatments were more frequently administered during the first years of the study, as catheter ablation became more frequent as the years passed by. After a median follow-up of 28 months, no differences either in survival (32% vs. 29% P = 0.8) or in ES recurrence (38% in ablated vs. 57% in non-ablated patients, P = 0.29) were observed between groups. Low left ventricle ejection fraction (LVEF) was the only variable associated with ES recurrence in ablated patients. When including patients with LVEF > 25%, ES recurrence was significantly lower in ablated patients (24 months estimated risk of ES recurrence was 21% vs. 62% in ablated and non-ablated patients, respectively); however, no benefit in survival was observed.nnnCONCLUSIONnOur data suggest that in most patients, especially those with an LVEF > 25%, catheter ablation following a first ES episode, decreases the risk of ES recurrence, without increasing survival.

Implantable loop recorder: towards a gold standard for the diagnosis of syncope?

Syncope is a transient symptom and not a disease. Typically, patients are asymptomatic at the time of evaluation and the opportunity to capture a spontaneous event during diagnostic testing is rare. As a result, diagnostic evaluation has focused on the detection of abnormalities that could plausibly cause loss of consciousness. This type of reasoning necessarily leads to uncertainty in establishing a cause. In other words, the causal relation between an abnormality found during the diagnostic workup and syncope is often presumptive. Indeed, in the tests used to evaluate the aetiology of syncope, it is not possible to measure test sensitivity and specificity, owing to the lack of a reference standard for most of the tests. Because of the episodic behaviour of syncope, the opportunity of correlating the spontaneous syncopal episodes with an abnormal finding can be considered as a reference standard.nnAn implantable ECG event monitor has recently become available (Reveal, Medtronic). This device is placed subcutaneously under local anaesthesia, and has a battery life of 15–18 months. The device has a solid state loop memory and, with the current version, the ECG of up to 40 minutes before and two minutes after activation can be stored. With these characteristics, if patients activate the device when consciousness has been restored, there is a high probability of having a correlation of ECG signals and syncope. In the first reported experience, the device was used in a heterogeneous population of 85 patients affected by unexplained syncope,1 which included patients with and without structural heart disease as well as patients with and without abnormalities in baseline ECG. Syncope-ECG correlation was achieved in 27% of patients and presyncope-ECG correlation in 32%; the rhythm recorded during the event was heterogeneous, thus reflecting the various clinical settings of the population enrolled: 29 patients were in …

Implantation of single-lead atrioventricular permanent pacemakers guided by electroanatomic navigation without the use of fluoroscopy

AIMSnFluoroscopy is the standard and almost unique tool used for cardiac imaging during permanent pacemaker implantation, and its use implies exposure of patients and operators to radiation. The usefulness for this purpose of electroanatomic systems not based on fluoroscopy is unknown. Our aim was to study the feasibility of implanting single-lead VDD pacemakers without the use of fluoroscopy.nnnMETHODS AND RESULTSnEnSite NavX, a catheter navigation tool based on the creation of a voltage gradient across the thorax of the patient, was used as an exclusive imaging tool during the implantation of single-lead atrioventricular (VDD) permanent pacemakers in 15 consecutive patients with atrioventricular block and normal sinus node function. A retrospective series of 15 consecutive patients in whom VDD pacemakers were implanted under fluoroscopic guidance was used as a control group. The pacemaker could be implanted in all patients. Time spent to obtain the right ventricle anatomy was 10.1 +/- 5.4 min and time to place the lead in an adequate position was 10.1 +/- 7.8 min. Total implant time was 59.3 +/- 15.6 min (51.5 +/- 12.3 min in the control group; P = 0.14). In one patient, a short pulse of radioscopy was needed for a correct catheterization of the subclavian vein. No complications were observed during the procedure. One lead dislodgement that required re-operation was detected 24 h after implantation. At 3 months follow-up, all pacemakers were functioning properly, with adequate pacing and sensing thresholds.nnnCONCLUSIONnElectroanatomic navigation systems such as NavX can be used for cardiac imaging during single-lead atrioventricular pacemaker implantation as a reliable and safe alternative to fluoroscopy.

Prognostic value of the electrocardiogram in patients with syncope: Data from the Group for Syncope Study in the Emergency Room (GESINUR)

BACKGROUNDnThe Group for Syncope Study in the Emergency Room (GESINUR) was a Spanish multicenter, prospective, observational study that evaluated the clinical presentation and acute management of loss of consciousness in Spain. Several studies have shown that an abnormal ECG is a poor prognostic factor in patients with syncope. However, the prognostic significance of each ECG abnormality is not well known.nnnOBJECTIVEnThe purpose of this study was to study the association between specific ECG abnormalities and mortality in patients with syncope from the GESINUR study.nnnMETHODSnAll patients in the GESINUR study who had syncope and had available, readable ECG and 12-month follow-up data were included in this retrospective observational study (n = 524, age 57 ± 22 years, 50.6% male). ECG abnormalities were analyzed and assessed to evaluate whether an association with all-cause mortality existed at 12 months.nnnRESULTSnECGs were classified as abnormal in 344 patients (65.6%). Thirty-three patients died during follow-up (6.3%), but only 1 due to sudden cardiovascular death. Atrial fibrillation (odds ratio [OR] 6.8, 95% confidence interval [CI] 2.8-16.3, P <.001), intraventricular conduction disturbances (OR 3.8, 95% CI 1.7-8.3, P = .001), left ventricular hypertrophy ECG criteria (OR 6.3, 95% CI 1.5-26.3, P = .011), and ventricular pacing (OR 21.8, 95% CI 4.1-115.3, P <.001) were the only independent ECG predictors of all-cause mortality.nnnCONCLUSIONnAlthough an abnormal ECG in patients with syncope is a common finding, only the presence of atrial fibrillation, intraventricular conduction disturbances, left ventricular hypertrophy ECG criteria, and ventricular pacing is associated with 1-year all-cause mortality.

Dual-Chamber Pacing With Closed Loop Stimulation in Recurrent Reflex Vasovagal Syncope: The SPAIN Study

BACKGROUNDnPacing in vasovagal syncope remains controversial.nnnOBJECTIVESnThe authors evaluated dual-chamber pacing with closed loop stimulation (DDD-CLS) in patients with cardioinhibitory vasovagal syncope.nnnMETHODSnThis randomized, double-blind, controlled study included Canadian and Spanish patients agexa0≥40 years, with high burden syncope (≥5 episodes,xa0≥2 episodes in the past year), and a cardioinhibitory head-up tilt test (bradycardiaxa0<40 beats/min for 10xa0s or asystole >3 s). Patients were randomized to either DDD-CLS pacing for 12xa0months followed by sham DDI mode pacing at 30 pulses/min for 12xa0months (group A), or sham DDI mode for 12xa0months followedxa0by DDD-CLS pacing for 12xa0months (group B). Patients in both arms crossed-over after 12xa0months of follow-up orxa0when a maximum of 3 syncopal episodes occurred within 1xa0month.nnnRESULTSnA total of 46 patients completed the protocol; 22 were men (47.8%), and mean age was 56.30 ± 10.63 years. The mean number of previous syncopal episodes was 12 (range 9 to 20). The proportion of patients withxa0≥50% reduction in the number of syncopal episodes was 72% (95% confidence interval [CI]: 47% to 90%) with DDD-CLS compared withxa028% (95% CI: 9.7% to 53.5%) with sham DDI mode (pxa0=xa00.017). A total of 4 patients (8.7%) had events duringxa0DDD-CLS and 21 (45.7%) during sham DDI (hazard ratio: 6.7; 95% CI: 2.3 to 19.8). Kaplan-Meier curve was significantlyxa0different between groups in time to first syncope: 29.2xa0months (95% CI: 15.3 to 29.2xa0months) versusxa09.3xa0months (95% CI: 6.21xa0months, NA; pxa0< 0.016); odds ratio: 0.11 (95% CI: 0.03 to 0.37; pxa0< 0.0001).nnnCONCLUSIONSnDDD-CLS pacing significantly reduced syncope burden and time to first recurrence by 7-fold,xa0prolonging time to first syncope recurrence in patients agexa0≥40 years with head-up tilt test-induced vasovagalxa0syncopexa0compared with sham pacing. (Closed Loop Stimulation for Neuromediated Syncope [SPAINxa0Study];xa0NCT01621464).

Medium-term results of cryoballoon ablation of the pulmonary veins in patients with paroxysmal and persistent atrial fibrillation. First experience of a Spanish center.

PurposeCryoballoon ablation of the pulmonary veins (CAPV) is a new technique that could have similar results to radiofrequency procedures, but with fewer complications. We analyzed the outcomes and safety of this technique in a consecutive cohort of patients with atrial fibrillation (AF).MethodsA total of 63 patients with paroxysmal (nu2009=u200940) or persistent (nu2009=u200923) AF were studied. Patient follow-up was performed at 3xa0months and then every 6xa0months with 72-h continuous electrocardiographic recordings.ResultsA total of 262 pulmonary veins were treated; 60.3xa0% of the cases presented normal pulmonary vein drainage with 4 pulmonary veins, and 23.8xa0% of the cases presented a common left-sided antrum. Complete isolation of all veins was achieved in 95.2xa0% of cases with 10.3u2009±u20092.8 (meanu2009±u2009standard deviation) applications per patient. Transient right phrenic nerve injury was the most common complication (4.7xa0%). Median follow-up was 5.5xa0months. The probability of being free of recurrence at 1 and 2xa0years was, respectively, 86.2 and 72.2xa0% for paroxysmal AF and 49 and 36.4xa0% for persistent AF (Pu2009=u20090.012). Patients with structural heart disease experienced recurrence more often than patients with a normal heart (62.5 versus 24.5xa0%; Pu2009=u20090.03).ConclusionsCAPV appears to be a safe and effective procedure for the treatment of patients with AF, particularly those with paroxysmal AF and no structural heart disease.