Cryoablation for atrial fibrillation and antiarrhythmic drug pretreatment: a single referral center experience

OBJECTIVE

Pulmonary vein isolation (PVI) ablation has emerged as the gold standard of ablative strategies to treat medically refractory paroxysmal and persistent atrial fibrillation (AF). Regardless of the superiority of catheter ablation based on PVI over antiarrhythmic drug therapy, recurrence rates of AF remain higher than desired. PVI via cryoablation has rapidly become a mainstream treatment for AF, due to its effectiveness and fast learning curve. Our objective was to assess the safety and efficacy of cryoablation in a single referral center.

PATIENTS AND METHODS

This is a retrospective analysis of results after cryoablation treatment of AF over three years. 146 patients with AF underwent a cryoablation procedure in our clinical center and were followed-up for three years after the procedure. All patients received cryoablation of the pulmonary veins, although concomitant procedures were performed in 6 patients (re-ablation), including radiofrequency and cryoablation.

RESULTS

Cryoablation was clinically successful in 90.83% of the patients with paroxysmal AF and 60% of those with persistent AF. The clinical success of cryoablation was correlated with pretreatment with amiodarone and in the case of re-ablation. Concerning postoperative complications, major bleeding was correlated with female gender, treatment with rivaroxaban and amiodarone.

CONCLUSIONS

Among large trials, freedom from recurrent AF is about 65% with follow-up limited to 1 to 2 years. PVI via balloon cryoablation is a safe and efficient guideline-based treatment for AF, producing a durable event-free result in most patients out to 3 years with better outcomes than previously reported.

Cryoablation for atrial fibrillation and antiarrhythmic drug pretreatment: a single referral center experience

OBJECTIVE

Pulmonary vein isolation (PVI) ablation has emerged as the gold standard of ablative strategies to treat medically refractory paroxysmal and persistent atrial fibrillation (AF). Regardless of the superiority of catheter ablation based on PVI over antiarrhythmic drug therapy, recurrence rates of AF remain higher than desired. PVI via cryoablation has rapidly become a mainstream treatment for AF, due to its effectiveness and fast learning curve. Our objective was to assess the safety and efficacy of cryoablation in a single referral center.

PATIENTS AND METHODS

This is a retrospective analysis of results after cryoablation treatment of AF over three years. 146 patients with AF underwent a cryoablation procedure in our clinical center and were followed-up for three years after the procedure. All patients received cryoablation of the pulmonary veins, although concomitant procedures were performed in 6 patients (re-ablation), including radiofrequency and cryoablation.

RESULTS

Cryoablation was clinically successful in 90.83% of the patients with paroxysmal AF and 60% of those with persistent AF. The clinical success of cryoablation was correlated with pretreatment with amiodarone and in the case of re-ablation. Concerning postoperative complications, major bleeding was correlated with female gender, treatment with rivaroxaban and amiodarone.

CONCLUSIONS

Among large trials, freedom from recurrent AF is about 65% with follow-up limited to 1 to 2 years. PVI via balloon cryoablation is a safe and efficient guideline-based treatment for AF, producing a durable event-free result in most patients out to 3 years with better outcomes than previously reported.

Clinical implementation of cardiac resynchronization therapy-regional disparities across selected ESC member countries

Background

The present analysis aimed to estimate the penetration of cardiac resynchronization therapy (CRT) on the basis of the prevalence and incidence of eligible patients in selected European countries and in Israel.

Methods and Results

The following countries were considered: Italy, Slovakia, Greece, Israel, Slovenia, Serbia, the Czech Republic, Poland, Romania, Hungary, Ukraine, and the Russian Federation. CRT penetration was defined as the number of patients treated with CRT (CRT patients) divided by the prevalence of patients eligible for CRT. The number of CRT patients was estimated as the sum of CRT implantations in the last 5 years, the European Heart Rhythm Association (EHRA) White Book being used as the source. The prevalence of CRT indications was derived from the literature by applying three epidemiologic models, a synthesis of which indicates that 10% of heart failure (HF) patients are candidates for CRT. HF prevalence was considered to range from 1% to 2% of the general population, resulting in an estimated range of prevalence of CRT indication between 1000 and 2000 patients per million inhabitants. Similarly, the annual incidence of CRT indication, representing the potential target population once CRT has fully penetrated, was estimated as between 100 and 200 individuals per million. The results showed the best CRT penetration in Italy (47–93%), while in some countries it was less than 5% (Romania, Russian Federation, and Ukraine).

Conclusion

CRT penetration differs markedly among the countries analyzed. The main barriers are the lack of reimbursement for the procedure and insufficient awareness of guidelines by the referring physicians.

Level of patient and operator dose in the largest cardiac centre in Greece

The objective of this study was to investigate the patient and staff doses in the most frequent interventional cardiology (IC) procedures performed in Onassio, the largest Cardiac Centre in Greece. Data were collected from three digital X-ray systems for 212 coronary angiographies, 203 percutaneous transluminal coronary angioplasties (PTCA) and 134 various electrophysiological studies. Patient skin dose was measured using suitably calibrated slow radiotherapy films and cardiologist dose using suitably calibrated thermoluminescent dosemeters placed on left arm, hand and foot. Patient median dose area product (DAP) (all examinations) ranged between 6.7 and 83.5 Gy cm2. Patient median skin dose in PTCA was 799 mGy (320-1660 mGy) and in RF ablation 160 mGy (35-1920 mGy). Median arm, hand and foot dose to the cardiologist were 12.6, 27 and 13 microSv, respectively, per procedure. The great range of radiation doses received by both patients and operators confirms the need for continuous monitoring of all IC techniques.

The incidence of malignant vasovagal syndrome in patients with recurrent syncope

We reviewed 322 patients with recurrent syncope between 1984 and 1988. Investigation included limited intracardiac electrophysiological study in all cases with programmed extra-stimulus studies in 48 cases. In 93 patients (29%), all investigations were normal, (including negative extrastimulus in 30). In the other 229 cases syncope was explained by AV-block (n = 111, 34%), sinus node disease (n = 68, 21%), carotid sinus syndrome (n = 32, 10%) and inducible sustained tachyarrhythmia (n = 18, 6%). Prolonged 60 degrees head-up tilt was performed in 71 out of 93 patients with unexplained syncope, and reproduced vasovagal syncope and presenting symptoms in 53 (75%), or 16% of the whole population reported. These patients were diagnosed as having malignant vasovagal syndrome. Positive tilts were significantly less common in a group of 27 subjects of similar age without a history of syncope (7%), and a random sample of 37 patients with atrioventricular block (n = 16), sick sinus syndrome (n = 18) and inducible tachyarrhythmia (n = 3), (19%, 11% and 0% respectively, P less than 0.01). From this retrospective review it appears, therefore, that tilt testing is a valuable provocative tool for vasovagal syncope and may reduce the number of syncopal patients that remain undiagnosed, although these early observations do not allow an exact appraisal of the sensitivity and specificity of the tilt test.

Natural history of sinus node chronotropy in paced patients

The natural history of chronotropic incompetence is not clear. To assess this, we evaluated corrected sinus node recovery time (cSNRT) and sinus node chronotropy at rest and during exercise in two groups of syncopal patients with sinus node disease. Group A comprised patients with resting bradycardia but normal cSNRT and group B had resting bradycardia and prolonged cSNRT (greater than 1000 ms). An additional two groups (C and D) were studied. Group C comprised patients with complete AV (CAVB) and no evidence of sinus node disease and group D were asymptomatic controls of similar age. At diagnosis, patients with symptomatic bradycardia but normal cSNRT and no evidence of carotid sinus syndrome (group A) had resting bradycardia and impaired peak heart rate (PHR-I) on exercise compared to controls (P less than 0.001 and P less than 0.05, respectively), but no reduction in exercise duration. At follow-up group A patients demonstrated an increase in resting rate that was significantly slower than the controls (P less than 0.01). Peak heart rate (PHR-II) also remained significantly slower (P less than 0.05). There was no difference in exercise duration between groups A and D at follow-up. Group B was further subdivided according to follow-up findings of preservation of atrial activity in seven patients (group B-1) and junctional rhythm without any atrial activity in four patients (group B-2). Retrospective analysis showed no significant difference in resting heart rate at initial examination but group B-2 showed a significantly lower peak heart rate on exercise compared with B-1 (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Methodology of head-up tilt testing in patients with unexplained syncope

Prolonged 60 degree head-up tilt has been shown to be valuable in the investigation of unexplained syncope, diagnosing neurally mediated bradycardia/hypotension or malignant vasovagal syndrome. To evaluate the methodology of tilt testing, the following were examined: reproducibility of results, tilt duration, angle of tilt, method of tilt support and effect of age in patients and control subjects. Seventy-one patients with recurrent unexplained syncope underwent 60 min of 60 degree tilt; 53 (75%) had an abnormal test with vasovagal syncope at 24 +/- 10 min (mean +/- SD). Tilting to 60 degrees resulted in an abnormal test in only 2 (7%) of 27 control subjects without cardiovascular symptoms (p less than 0.001); and 5 (15%) of 34 patients with syncope and documented conduction tissue disease (p less than 0.001). Of 15 youthful fainters, 3 (20%) had vasovagal reactions as did 1 (8%) of 12 asymptomatic youthful control subjects. These 12 control subjects also underwent tilting with a saddle support and 7 (67%) had vasovagal reactions. It is concluded that the duration of tilting at 60 degrees should be 45 min (mean time to syncope +2 x SD in the 53 patients with abnormal results). Twenty percent of patients with an abnormal tilt test may not demonstrate syncope with repeat tilting. Saddle tilt testing in unexplained syncope may result in a loss of specificity. Tilting at less than 60 degrees results in a loss of sensitivity. Head-up tilt may be less useful in youthful subjects with vasovagal syncope than in other subjects.

Dual chamber pacing aborts vasovagal syncope induced by head-up 60 degrees tilt

To determine if pacing might prevent syncope in cardioinhibitory 'Malignant Vasovagal Syndrome' (also known as 'Neurally-Mediated Bradycardia/Hypotension'), a study of dual chamber pacing during head-up 60 degrees tilt was undertaken. Paired invasive tilts were performed in 10 patients who had a history of recurrent syncope, normal routine investigations including electrophysiological study and prior tilt-induced vasovagal syncope. Vasovagal reactions of identical severity were produced by prolonged 60 degrees head-up tilt on consecutive days in seven out of 10 patients. On day 2, without pacing, seven patients had tilt-induced vasovagal reactions and six became syncopal during the reaction. On day 3, with temporary DVI pacing with rate hysteresis, seven patients had tilt-induced vasovagal reactions and 1 patient was syncopal. Syncope was aborted in the other five patients. DVI pacing significantly improved cardiac index (CI) (one +/- 0.2 to 1.6 +/- 0.3 L/min/m2, P less than 0.01) and mean arterial blood pressure (MABP) (30 +/- 11 to 48 +/- 12 mmHg, P less than 0.01) during vasovagal reactions on day 3 compared with day 2. The mean period of time that patients could tolerate in the tilted position after the onset of the tilt-induced vasovagal reaction was significantly prolonged by pacing from 0.9 +/- 1.2 to 3.2 +/- 1.6 min (P less than 0.01). Dual chamber pacing may abort syncope in 85% of patients with cardioinhibitory malignant vasovagal syndrome. Pacing may prolong consciousness sufficiently during a vasovagal reaction to allow injury to be avoided.

c-AMP and ANP levels in VVI and DDD pacing with different AV delays during daily activity and exercise

Nine patients (three males) mean age 68 +/- 8 years, having complete heart block, and paced in the DDD mode were examined in VVI and DDD pacing with 100 and 150 ms atrioventricular delays (AVD) during rest and exercise. Plasma atrial natriuretic peptide (ANP) and cyclic AMP (c-AMP) were measured at rest and at peak exercise test. ANP plasma levels at rest were significantly higher in VVI pacing compared to 150 AVD (P less than 0.03). On exercise, ANP release was statistically increased only in DDD with 150 ms AVD, while in VVI it remained in high levels at exercise but no significant change was found (p:ns). c-AMP during rest was unchanged in any pacing mode or AVD, but on exercise DDD pacing with short AVD (100 ms) released lower c-AMP plasma levels, than at rest (p:ns). DDD pacing with long AVD (150 ms) during exercise produced statistically higher c-AMP plasma levels (P less than 0.05) than at rest. Also in VVI pacing the c-AMP plasma levels were statistically higher than at rest (P less than 0.02). Adrenergic activity seems to be lower during exercise in DDD pacing with shorter AVD (100 ms) than in DDD with 150 ms AVD or VVI pacing. No difference was found in c-AMP plasma levels at rest. ANP release was also found to be lower at exercise in DDD pacing with short AVD (100 ms) than in DDD with 150 ms AVD. ANP plasma levels at rest were statistically higher in VVI pacing.