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Background The use of temporary mechanical circulatory support (tMCS) during arrhythmia is increasing, although available evidence for this indication is limited, with significant gaps of knowledge regarding appropriate timing, management and configuration. This systematic review sought to analyze the use of tMCS in patients with life-threatening arrhythmia. Methods A systematic literature search identified 2529 references published until September 2019. Adult and pediatric patients diagnosed with all kind of life-threatening arrhythmia were included. tMCS was primarily compared to conventional non-tMCS therapies. Primary outcome measure was in-hospital or 30-day mortality. Results 19 non-randomized studies were selected, including 2465 adult and 82 pediatric patients. Primary outcome in tMCS patients varied widely (4–62%) with differences based on the use of prophylactic tMCS (4–21%) or rescue tMCS (58–62%). A substantial mortality benefit was observed among high-risk patients, as identified with PAINESD risk score or suffering from electrical storm and treated with prophylactic tMCS. During ablation procedures, tMCS patients showed higher rates of induced ventricular tachycardias (VTs), ablated VTs, VT termination and non-inducibility after ablation. Extracorporeal membrane oxygenation (ECMO) was applied in pediatric cases as hemodynamic protection for aggressive antiarrhythmic medical treatment with >80% survival. Conclusions Prophylactic tMCS is associated with improved survival as compared to rescue or no-tMCS in patients with life-threatening arrhythmia, and may be considered in patients with high PAINESD risk score or suffering from electrical storm. ECMO can be advised as rescue and support therapy in pediatric cases requiring aggressive antiarrhythmic medical treatment.

Recognition of the presence and role of decremental fibers during wide QRS tachycardia requires carefully executed intracardiac studies.This study sought to determine the value of the atrioventricular (AV) conduction time during pre-excited tachycardia to differentiate a fast from a decrementally conducting accessory pathway (AP).Fifty-one patients with 56 pre-excited tachycardias were included in the study: Group I: 27 patients with 31 antidromic tachycardia (ADT) using an atriofascicular pathway, Group II: 2 patients with pre-excited tachycardia due to bystander AV conduction, Group III: 3 patients with ADT and a short AV Mahaim fiber, and Group IV: 19 patients with 21 ADT using a fast conducting right-sided AP. The AV interval was measured in the His bundle electrogram and related to the tachycardia cycle length (TCL) by making an AV/TCL index.An AV intervalor = 150 ms during pre-excited tachycardia yielded a 91% sensitivity, 90% specificity, positive predictive value of 94%, and negative predictive value of 83% for AV conduction over a decrementally conducting pathway, whereas aor =0.55 AV/TCL index yielded a sensitivity of 89%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 84%. In 3 of 4 patients with Mahaim fibers and a0.55 AV/TCL index, a prolonged ventriculoatrial (VA) conduction time was found.An AV intervalor =150 ms during pre-excited tachycardia is a fast and reliable method for detecting a decrementally conducting AP. Correcting the AV interval by the tachycardia cycle length improved specificity and positive predictive accuracy.

Objectives This study was designed to evaluate the long-term effect of segmental pulmonary vein (PV) cryoablation in patients with recent-onset paroxysmal atrial fibrillation (PAF). Background Patients with PAF have more triggers to initiate and less substrate to sustain atrial fibrillation (AF). Elimination of the potential initiators alone may be sufficient to abolish the arrhythmia. Methods Patients with PAF were prospectively recruited from July 2001 to July 2005. If the triggers for AF were identified, PV cryoisolation of the arrhythmogenic vein(s) was performed. Otherwise, all PVs were isolated. Results Seventy patients with minimal or no heart disease (54 men; age 40 ± 10 years) were enrolled. The duration of AF was 4 ± 1 year. The left ventricular ejection fraction and left atrial size were 59 ± 8% and 41 ± 5 mm, respectively. An arrhythmogenic PV was found in 10 patients (14%). Complications occurred in 3 patients (4%). No PV stenosis or esophageal injury was detected during a mean follow-up of 33 ± 15 months. Thirty-four patients (49%) achieved complete success (no AF and no antiarrhythmic drugs [AAD]); 15 patients (22%) had no recurrences with AAD; and 8 patients (11%), still with sporadic bursts of AF, improved >50% with AAD. Overall, 82% of the patients benefited from the procedure. Patients in whom the arrhythmogenic PV was identified and isolated had no recurrences. Conclusions Pulmonary vein cryoisolation is effective in 82% of patients with recent-onset PAF during a mean follow-up of 33 ± 15 (range 15 to 60) months. If the arrhythmogenic PV is identified and isolated, the long-term outcome is excellent, indicating no need to isolate all PVs.

There is debate concerning the distal insertion of Mahaim fibers. Some findings favor an atriofascicular fiber connected with the distal right bundle branch. Other findings favor a long atrioventricular (AV) structure inserting into the myocardium. A patient having a decrementally conducting accessory pathway is reported. Proximal and distal Mahaim potentials were recorded during sinus rhythm, atrial pacing, and antidromic tachycardia. Both proximal and distal M potentials always preceded the QRS complex during sinus rhythm and antidromic tachycardia earlier than the right bundle branch potential. During tachycardia, the distal M potential was recorded 6 ms before the retrograde right bundle potential. Other arguments consistent with an AV connection were a change in the QRS configuration during tachycardia after the first radiofrequency pulse at the site of the distal M potential and absence of right bundle branch block after successful ablation. Conduction through the proximal part of the Mahaim fiber was unaltered after ablation, as assessed by recording the proximal M potential. Electrophysiologic evidence is presented suggesting a long AV accessory pathway inserting close to the distal right bundle branch rather than an atriofascicular connection in this patient with a Mahaim fiber.

The aim of this study was to compare single-3-minute (single-3) with double-3-minute (double-3) cryothermia applications for treatment of atrial flutter (AFL).Previous animal studies have indicated the need for a double 5-minute cryothermal application to create large and permanent lesions.Forty patients (56 +/- 13 years old) with typical AFL (cycle length 229 +/- 35 ms) were randomized to single-3 (n = 20) or double-3 (n = 20) cryothermia applications at each site along the cavotricuspid isthmus (CTI). Cryoablation was performed with the CryoCor cryoablation system. A successful procedure was defined as noninducibility of AFL with the concomitant presence of bidirectional CTI conduction block under isoproterenol infusion.All but 1 patient (95%) of the single-3 group and all patients (100%) of the double-3 group were successfully ablated. The number of sites needed to create isthmus conduction block was 9 +/- 4 (single-3) and 8 +/- 2 (double-3) (NS). Fluoroscopy time did not differ between the two groups (single-3: 31 +/- 14; double-3: 36 +/- 17 min, NS). The procedure time of the single-3 group was significantly shorter compared to the procedure time of the double-3 group (mean procedure duration 132 +/- 64 vs 159 +/- 50 min, P.04). After a mean follow-up of 11.7 +/- 4.7 months, two recurrences of AFL occurred in the double-3 group.Single cryothermia applications of 3 minutes produce permanent CTI conduction block in patients with typical AFL and significantly reduce procedure duration.

Objectives The purpose of the study was to identify the electrocardiographic (ECG) characteristics of the Mahaim fiber. Background Mahaim fibers are slowly conducting accessory pathways reaching into the right ventricle. They often play a role in tachycardias. Methods We retrospectively analyzed 40 patients with Mahaim fibers. Five patients had associated Wolff-Parkinson-White syndrome and were excluded from the study. Two patients had a short atrioventricular decremental accessory pathwayand were also excluded. The remaining 33 patients had a tachycardia with anterograde conduction over a Mahaim fiber. Twenty were female. Their mean age was 24 ± 10 years. Results The most common pattern of minimal preexcitation during sinus rhythm was an rS pattern in lead III. This was found in 20 patients. There was a match between the presence of rS in lead III during sinus rhythm and left axis deviation during tachycardia with anterograde conduction over the Mahaim fiber. After ablation, a different QRS pattern emerged in lead III, indicating the absence of conduction over the Mahaim fiber. To obtain information on the prevalence of an rS pattern in lead III in age-matched controls with palpitations and without structural heart disease, the 12-lead ECG of 200 young individuals were examined. An rS pattern in lead III was found in 6%. Conclusions A narrow QRS with an rS pattern in lead III during sinus rhythm in a patient with a history of palpitations should alert the physician to the possibility of a Mahaim fiber. During tachycardia, these patients typically show a left bundle branch block-like QRS complex with left axis deviation.

Objectives This study investigated whether pain catastrophizing is associated with distress and perceived disability in patients with atrial fibrillation, whether pain catastrophizing predicts pain and fear during a medical procedure of atrial cardioversion, and whether pain catastrophizing influences the effects of an opioid analgesic during internal cardioversion. Methods A secondary analysis is performed upon data from a double-blind placebo-controlled trial during which the effect of intranasal butorphanol tartrate (INB) was evaluated in patients with atrial fibrillation using a step-up internal atrial cardioversion protocol. Before the procedure, patients completed measures of pain catastrophizing, mood, distress and perceived disability. After each shock, patients completed measures of pain and fear. Results We found that pain catastrophizing predicted the affective pain rating of the first shock, and the fear increase during subsequent shocks. There was no effect of INB. However, when controlling for the differences in pain catastrophizing, INB significantly reduced fear as compared to placebo. This suggests that the effects of INB during atrial cardioversion were overshadowed by the effects of pain catastrophizing. Conclusions It is recommended that in future atrial cardioversion trials, stratification based on pain catastrophizing be performed. Reducing catastrophizing thinking about pain through cognitive–behavioral techniques are likely to reduce levels of fear during internal atrial cardioversion and may increase the effectiveness of concomitant analgesics.

Objectives We sought to evaluate the efficacy and safety of pulmonary vein (PV) isolation using transvenous cryoablation for the treatment of atrial fibrillation (AF). Background Although electrical isolation of PVs with radiofrequency energy for the treatment of AF is feasible, it is associated with a significant risk of PV stenosis. Cryoablation is a new alternative therapy allowing ablation of tissue while preserving its underlying architecture. Methods In 52 patients with paroxysmal (n = 45) or persistent (n = 7) AF, PV isolation using the CryoCor cryoablation system (CyroCor Inc., San Diego, California) with a 10F deflectable transvenous catheter was performed as guided by ostial PV potentials. Cryoablation was applied twice at each targeted site (2.5 to 5 min/application). Computed tomography (CT) of the thorax was performed at baseline and at 3 and 12 months to evaluate for PV stenosis. Results All targeted PVs were completely isolated in 49 (94%) of 52 of patients. Of 152 PVs targeted, 147 (97%) were successfully isolated (mean 3.0 PVs isolated per patient). After a mean period of 12.4 ± 5.5 months of follow-up, 37 (71%) of 52 patients had no recurrence of AF or were clinically improved, including 29 patients (56%) who had no recurrence of AF with (n = 11) or without the use of anti-arrhythmic drugs. At 3 and 12 months, the CT scan showed no evidence of PV stenosis associated with cryoablation in any patients. Conclusions Transvenous catheter cryoablation is an effective method to create PV electrical isolation for the treatment of AF. A clinically satisfactory result can be achieved in 71% of patients with AF, without the risk of PV stenosis.

The purpose of this study was to evaluate the use of a new 2-lead system for detection of atrial fibrillation (AF) and atrial defibrillation.In 16 patients undergoing elective cardioversion of AF, a 2-lead system was compared with the conventional 3-lead system in a randomized trial. The new 2-lead system consisted of a catheter with a distal bipolar right ventricular electrode pair and a proximal right atrial shock electrode coil and a separate decapolar defibrillation catheter in the coronary sinus. For the 3-lead system, an additional decapolar catheter was placed in the right atrium. AF and sinus rhythm signal amplitude detection and atrial defibrillation threshold (ADFT) were compared in each patient with both systems.Successful defibrillation was obtained in all patients. ADFT for the 2-lead system was significantly higher compared with the 3-lead system (370 +/- 112 vs 316 +/- 100 V, P.05; 9.3 +/- 5.2 vs 6.8 +/- 4.2 J, P.05). In contrast, there was an increase in impedance for the 3-lead system (77 +/- 16 ohms vs 68 +/- 13 ohms; P.05). AF had a lower signal amplitude compared with sinus rhythm for both systems (P.05), and the 2-lead system had a lower signal amplitude compared with the 3-lead system for both rhythms (P.05).The use of a 2-lead system with this configuration is not superior to the 3-lead system regarding AF signal amplitude detection and ADFT. Further study is needed with implantable-quality leads in place of the temporary catheters used in this study.

OBJECTIVESWe sought to evaluate the number and duration of device-treated and self-terminating, nontreated episodes of atrial fibrillation (AF) after implantation of the Metrix Atrioverter.BACKGROUNDA recent study has shown that the Atrioverter can rapidly restore sinus rhythm in patients with AF; however, the effect of the device on the clinical course of the arrhythmia in these patients is unknown.METHODSThe Atrioverter was implanted in 51 patients with symptomatic, recurrent, drug-refractory AF. The device was programmed to periodically monitor the cardiac rhythm. Defibrillation of AF episodes was performed under physician observation.RESULTSDuring a mean follow-up of 260 ± 144 days, 1,161 episodes of AF were observed during valid monitoring periods in 45 of 51 patients. Forty-one patients experienced 231 episodes for which they sought defibrillation therapy. The average duration of the treated episodes during valid monitoring periods (190 of 231 episodes in 39 of 41 patients) was significantly longer than that of the nontreated episodes (38 ± 44 vs. 10 ± 8 h; p < 0.05). The time between episodes requiring Atrioverter therapy increased, and the risk of having an episode requiring treatment decreased. No changes were observed in the number and duration of the short-lasting, nontreated episodes as time since implantation of the device increased.CONCLUSIONSIn patients with symptomatic, recurrent, drug-refractory AF, the frequency of long-lasting episodes, which were treated under observation with repeated defibrillation using the Atrioverter, decreased. The number and duration of short-lasting, nontreated episodes did not change during the 20-month study period. The effect of ambulatory use of the device on the recurrence of short-lasting episodes needs to be evaluated.

A 65-year-old man with persistent atrial fibrillation (AF) underwent laser balloon (HeartLight, CardioFocus, Marlborough, Massachusetts) ablation of all 4 pulmonary veins (PVs) 30 months ago. The minimal dose of 5.5 W was used for 30 s in areas overlapping with blood. Seven watts was used for

The safety of the combination of heparin and ridogrel therapy and its antiplatelet efficacy was examined in the setting of percutaneous transluminal coronary angioplasty (PTCA). In 32 patients without known aspirin intake for 10 days before PTCA, therapy with ridogrel (300-mg intravenous bolus) was begun just before PTCA and continued orally at a dose of 300 mg twice daily until discharge. Heparin was administered as a 10,000 IU bolus dose before PTCA and followed by an intravenous infusion at a rate of 1,000 IU/hour for 24 hours. Bleeding problems at the arterial entry site occurred in 13 patients, which required a blood transfusion in only 2 patients. One patient underwent emergency bypass surgery without specific problems of hemostasis. Ridogrel virtually eliminated thromboxane B2 from the serum (29,990 +/- 6,555 pg/0.1 ml before vs 63 +/- 7 pg/0.1 ml at 2 hours after ridogrel), with a concomitant increase in serum 6-keto-prostaglandin F1 alpha (511 +/- 34 pg/0.1 ml before vs 1,190 +/- 146 pg/0.1 ml at 24 hours after ridogrel). There were no acute reocclusions in the ridogrel-treated patients, whereas acute reocclusions occurred in 5.6% of the patients taking the standard aspirin + heparin regimen during the same period. Furthermore, at 6-month clinical follow-up patients treated with ridogrel compared favorably with those receiving standard treatment.

In some patients with atrial fibrillation, atrial flutter develops after administration of class IC antiarrhythmic drugs, the so-called class IC atrial flutter. Radiofrequency ablation of the right atrial isthmus results in clinical improvement in 85% of patients and provides an alternative management strategy for a subset of patients with therapy-resistant atrial fibrillation.

In a population of 690 patients with Wolff-Parkinson-White (WPW) syndrome referred to our hospital from January 1979 to February 1995, 15 patients (2.2%) had an aborted sudden death out of the hospital. This retrospective study examines their clinical and electrophysiologic characteristics. Gender, accessory pathway localization, and presence of multiple accessory pathways were compared between patients with and without spontaneous ventricular fibrillation (VF). Whereas gender and the presence of multiple accessory pathways did not significantly differ between both groups, septally located pathways occurred significantly more often in the VF group. In patients with aborted sudden death, spontaneous VF was found significantly more often in men (13 of 15). VF was the first manifestation of the WPW syndrome in 8 patients. The remaining 7 patients had documented episodes of atrial fibrillation, circus movement tachycardia, or both (n = 2). Ten of the 15 patients were exercising or under emotional stress at the time of aborted sudden death. Only 1 patient had 2 accessory pathways. The location of the accessory pathway was septal (midseptal or posteroseptal) in 11 patients, left lateral in 4, and right lateral in 1).

A 17-year-old girl was diagnosed with an asymptomatic Wolff-Parkinson-White pattern just before a major orthopedic operation. Three months after the surgery, she developed ventricular fibrillation—being the first manifestation of her Wolff-Parkinson-White syndrome. The patient was successfully reanimated. radiofrequency ablation permanently interrupted conduction over a right posteroseptal accessory pathway.

Recently, several studies of cryoablation using balloon technology versus radiofrequency ablation of the pulmonary veins have shown that cryoablation of paroxysmal atrial fibrillation (PAF) promises to be an effective therapy with success rates similar to that of radiofrequency ablation. Cryothermal energy is known to be safer than other energy sources. The most frequently occurring complication of cryoablation by using a balloon is phrenic nerve palsy, which often occurs by positioning the balloon deep in a pulmonary vein (PV). We report a case of a 65-year old man with PAF in whom we performed a successful PV isolation using a 23-mm cryoballoon (Arctic Front, Medtronic Inc, Quebec Canada). The application of cryothermal energy in the left inferior PV [LIPV] was relatively deep in the PV (Figure 1A, arrows pointing to balloon [BL]). Temperatures reached 64°C. Four days after the procedure, the patient presented at the hospital with hemoptysis. A thoracic computed tomography (CT) scan showed no abnormalities. Bronchoscopy showed an erosion with blood effusion (diameter 3 to 4 mm) on the ventral side at the division of