Antithrombotic or anti-platelet agents in patients undergoing permanent pacemaker implantation.

BACKGROUND AND OBJECTIVES: The growing implantations of electrophysiological devices in the context of increasing rates of chronic antithrombotic therapy in cardiovascular disease patients underscore the importance of an effective periprocedural prophylactic strategy for prevention of bleeding complications. We assessed the risk of significant bleeding complications in patients receiving anti-platelet agents or anticoagulants at the time of permanent pacemaker (PPM) implantation. SUBJECTS AND METHODS: We reviewed bleeding complications in patients undergoing PPM implantation. The use of aspirin or clopidogrel was defined as having taking drugs within 5 days of the procedure and warfarin was changed to heparin before the procedure. A significant bleeding complication was defined as a bleeding incident requiring pocket exploration or blood transfusion. RESULTS: Permanent pacemaker implantations were performed in 164 men and 96 women. The mean patient age was 73±11 years old. Among the 260 patients, 14 patients took warfarin (in all of them, warfarin was changed to heparin at least 3 days before procedure), 54 patients took aspirin, 4 patients took clopidogrel, and 25 patients took both. Significant bleeding complications occurred in 8 patients (3.1%), all of them were patients with heparin bridging (p<0.0001). Heparin bridging markedly increased the length of required hospital stay when compare with other groups and the 4 patients (1.5%) that underwent the pocket revision for treatment of hematoma. CONCLUSION: This study suggests that hematoma formation after PPM implantation was rare, even among those who had taken the anti-platelet agents. The significant bleeding complications frequently occurred in patients with heparin bridging therapy. Therefore, heparin bridging therapy was deemed as high risk for significant bleeding complication in PPM implantation.

Clinical outcomes of brief versus prolonged unfractionated heparin infusion after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction in the drug-eluting stent era: real-world, single-centre experience.

OBJECTIVE: Optimal dose and duration of intravenous unfractionated heparin (UFH) infusion after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) are unknown when glycoprotein IIb/IIIa inhibitors (GPIs) are not used. We evaluated the clinical outcomes in patients who received brief versus prolonged UFH infusion following primary PCI for STEMI in the era of drug-eluting stents (DES). METHODS: We studied 273 (216 men, 63 +/- 12 years) consecutive patients who underwent primary PCI with DES implantation for STEMI between December 2003 and May 2009. All patients received currently recommended loading and maintenance doses of aspirin and clopidogrel. In-hospital and cumulative 30-day rates of major adverse cardiovascular events (MACEs) and major bleeding were compared between patients receiving brief (< 48 (26 +/- 15) hours, group 1) and those receiving prolonged (> or = 48 (83 +/- 38) hours, group 2) infusion of intravenous UFH following index procedure. RESULTS: The demographic and baseline angiographic characteristics were similar between the two groups. In-hospital and cumulative 30-day MACEs rates and major bleeding events rates were not statistically different between groups. CONCLUSION: In this single-centre experience, in patients with STEMI who underwent primary PCI in the era of DES, a routine post-procedure course of UFH infusion for more than 48 hours was not associated with any significant benefits. Further study is warranted to determine the optimal duration and dose of administration of UFH infusion following primary PCI.

Progressive familial heart block type I in a korean patient.

A 29-year-old man was referred to the emergency department with a complaint of abdominal pain and dizziness. He had experienced two previous syncopal episodes. His family history revealed that his mother and his two uncles had received permanent pacemaker implantation. His initial heart rate was 49 beats per minute. The electrocardiography (ECG) showed atrial flutter and right bundle branch block (RBBB) with left anterior fascicular block (LAFB). On admission, 24-hour Holter showed ventricular pause up to 16 seconds during syncope. Radio frequency catheter ablation (RFCA) of atrial flutter was performed. The ECG revealed bifascicular block (RBBB and LAFB) and first-degree atrioventricular block. He received a permanent pacemaker implantation. His brother's and his sister's ECGs also showed trifascicular block and the pedigree showed autosomal dominant inheritance. This patient was diagnosed with a progressive familial heart block (PFHB) type I. This would be the first report of a PFHB type I case documented in Korea.

Coexisting sustained tachyarrthymia in patients with atrial fibrillation undergoing catheter ablation.

BACKGROUND AND OBJECTIVES: During the index procedure of catheter ablation (CA) for atrial fibrillation (AF), it is important to assess whether other atrial or ventricular tachyarrhythmia coexist. Their symptoms are often attributed to residual tachycardia after successful elimination of AF by CA. This tachycardia could also be non-pulmonary vein (PV) foci initiated AF. This study examined the coexistence of other sustained tachyarrhythmia of patients who underwent radiofrequency CA (RFCA) for AF. SUBJECTS AND METHODS: Four hundred fifty-nine consecutive patients (375 males, aged 53.4+/-11.4 years) who underwent RFCA for AF were investigated. Atrial and ventricular programmed stimulation (PS) with or without isoproterenol infusion were performed, and spontaneously developed tachycardias were analyzed. RESULTS: Fifteen patients (3.3% of total) were diagnosed to have other sustained arrhythmias that included slow-fast type atrioventricular nodal reentrant tachycardia (AVNRT, n=6), atrioventricular reentrant tachycardia (AVRT, n=5) that utilized left posteroseptal (n=4) and parahisian bypass tract (n=1), atrial tachycardia (AT, n=2) originating from the foramen ovale (n=1) and the ostium of coronary sinus (n=1), sustained ventricular tachycardia (VT, n=2) involving one from the apical posterolateral wall of left ventricule in a normal heart and one from an anterolateral wall in an underlying myocardial infarction (MI). These sustained tachycardias were neither clinically documented nor had structural heart diseases, with the exception of one patient with MI associated VT. Two patients had the triple tachycardia; one involved AVNRT, AVRT, and AF, and the other involved VT, AT, and AF. All associated tachycardias were successfully eliminated by RFCA. CONCLUSION: Fifteen (3.3%) patients with AF had coexisting sustained tachycardia. RFCA was successful in these patients. Identification of tachycardia by PS before RFCA for AF should be done to maximize the efficacy of the first ablation session.

Atrial activation time and pattern of linear triple-site vs. single-site atrial pacing after cardioversion in patients with atrial fibrillation.

AIMS: Multisite atrial pacing has been suggested to be effective in suppressing atrial fibrillation (AF), however, the effect of linear triple-site atrial pacing (LTSP) in humans has not been evaluated. We compared the effects of LTSP to single-site atrial pacing (SSP) on the atrial activation and wavefront propagation pattern in patients with persistent AF. METHODS AND RESULTS: In 10 patients with persistent AF, the effects of LTSP and SSP were evaluated by left atrial (LA) endocardial non-contact multielectrode array mapping and multipolar catheters. LTSP and SSP were delivered from the high right atrium (HRA), the distal coronary sinus (CS), and within the LA at the site showing maximal overlay of low-voltage zones during sinus rhythm and pacing at HRA and CS. Atrial activation time and pattern, P wave duration, and the prevention of AF induced by burst pacing were assessed with these pacing interventions. Compared with SSP, LTSP at the HRA, CS, and LA shortened atrial activation times (183 +/- 24 vs. 174 +/- 24 ms, 186 +/- 29 vs. 166 +/- 28 ms, and 171 +/- 40 vs. 163 +/- 39 ms; P < 0.05, respectively). P wave duration was shorter with LTSP than SSP at all three sites (141.7 +/- 35.1 vs. 146.9 +/- 38.5 ms, 138.1 +/- 34.6 vs. 145.7 +/- 33.7 ms, and 142.7 +/- 33.4 vs. 151.3 +/- 35.1 ms; P < 0.05, respectively). LTSP initially depolarized a larger area than SSP, and produced more uniform and planar wavefront propagation. LTSP prevented the burst-induction of AF during LA pacing in 3 of 10 patients, while SSP was never successful. CONCLUSION: In patients with persistent AF, LTSP provided more rapid and uniform activation of the atria compared with SSP, which was associated with prevention of burst-induction of AF in some patients. Further study is required to determine whether LTSP can modify the substrate of chronic AF, leading to frank AF suppression.

Left atrial mass with stalk: thrombus or myxoma?

A 63-year-old female was presented to emergency room with an abdominal pain. The patient had moderate mitral valve stenosis and atrial fibrillation. Abdominal computed tomography revealed right renal infarction. Transthoracic echocardiography showed a large mobile mass in the left atrium. Transesophageal two-and three-dimensional echocardiography showed a large mobile ovoid mass with a narrow stalk attached to the left atrial septum. It was thought to be a myxoma rather than thrombus. Anticoagulation with heparin was continued. When the operation was performed, there was no mass in the left atrium. It must be a thrombus and melt away.

Safety and convenience of continuous warfarin strategy during the periprocedural period in patients who underwent catheter ablation of atrial fibrillation.

BACKGROUND: We investigated the efficiency and convenience of a continuous warfarinization (CW) strategy during the periprocedural period of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) in comparison with the classic strategy of switching to heparin (SH). METHODS AND RESULTS: We compared CW (n = 49) and SH (n = 55, 3 days before RFCA) in 104 patients who underwent RFCA of AF (77 males, 55 +/- 12 years old, paroxysmal AF: persistent AF = 63:41). During the procedure, the activated clotting time (ACT) was maintained between 350 and 400 seconds, and a requirement of H, postablation INR, and periprocedural complications were compared. Results were as follows: (1) in the CW group, the preprocedural INR (1.85 +/- 0.61 vs 1.05 +/- 0.12, P < 0.001) and the proportions of INR > 2.0 after RFCA (1st postprocedure day 61.2% vs 5.5%, P < 0.001; 2nd postprocedure day 83.3% vs 21.8%, P < 0.005) were higher, and the heparin requirement was lower (2012 +/- 998 U/30 minutes vs 2921 +/- 795 U/30 minutes, P < 0.001) than in the SH group. (2) The incidences of hemorrhagic complications (18.2% vs 18.4%, P = NS) or the major bleeding rates (reduced hemoglobin >or= 4 g/dL, requiring blood transfusion; 3.6% vs 12.2%, P = NS) were not significantly different in the CW group than in the SH group. CONCLUSION: The periprocedural CW strategy maintains a more stable INR immediately after AF ablation without increasing hemorrhagic complications compared with the classic strategy of SH. Simple CW can replace SH in an experienced laboratory with a low risk of hemopericardium during AF ablation.

The relationship between endocardial voltage and regional volume in electroanatomical remodeled left atria in patients with atrial fibrillation: comparison of three-dimensional computed tomographic images and voltage mapping.

BACKGROUND: Long-standing atrial fibrillation (AF) changes left atrial (LA) morphology, and the LA size is related to recurrence after radiofrequency catheter ablation (RFCA). We hypothesize that LA morphology, based on embryological origin, affects the outcome of RFCA. METHODS: We analyzed 3D computed tomographic (CT) images of LA in 70 patients with AF (54 males, 55.6 +/- 10.5 years old, paroxysmal AF (PAF):persistent AF (PeAF) = 32:38) who underwent RFCA. Each LA image was divided into venous atrium (VA), anterior LA (ALA), LA appendage (LAA), and both antrum. Absolute and relative volumes were calculated, and the lengths of linear ablation sites were measured. RESULTS: (1) In patients with the mean LA voltage < or = 2.0 mV, LA volume, especially ALA, was larger (P < 0.01) compared to those with LA voltage > 2.0 mV. (2) The total LA volume was significantly larger (P < 0.01) and LAA voltages (P < 0.05) and conduction velocities (P < 0.05) were lower in patients with PeAF than in those with PAF. (3) In patients with recurrence, LA volume was generally larger (P < 0.01) than in those without recurrence. In PAF patients with recurrence, the relative volume of ALA was significantly larger (P < 0.01) than those without recurrence. CONCLUSIONS: Morphologically remodeled LA has low endocardial voltage, and enlargement of ALA is more significant in electroanatomically remodeled LA. The disproportional enlargement of ALA was observed more often in PAF patients with recurrence after ablation than those without recurrence.

Clinical significance of complete conduction block of the left lateral isthmus and its relationship with anatomical variation of the vein of Marshall in patients with nonparoxysmal atrial fibrillation.

BACKGROUND: The vein of Marshall (VOM), which exists along the left lateral isthmus (LLI), constitutes a muscular connection between the coronary sinus (CS) and the left atrium (LA). We hypothesized that anatomical variation of the VOM affects the bidirectional block of LLI and the clinical outcome in patients with nonparoxysmal atrial fibrillation (NPAF). METHODS: Among 73 patients with NPAF, 54 patients (47 male, 54.1 +/- 10.4 years old) with a clearly visible VOM (74.0%) were included. After circumferential antral ablation, double linear endocardial ablation of LLI was performed along the VOM. Unless LLI block was achievable by endocardial ablation, the ablation was performed inside the CS. RESULTS: LLI block was achievable in 35 patients (64.8%; 11.1% by endocardial ablation vs 53.7% by additional inside CS ablation; P < 0.01). In patients with failed LLI block, the VOM was significantly longer (P < 0.05) on the right anterior oblique (RAO) view than in those with successful LLI block. LA volume or LLI length measured by CT image were not different (P = NS). During 11.4 +/- 5.0 months follow-up, early recurrences within 3 months (47.4% vs 28.6%, P = NS) and recurrences after 3 months (10.5% vs 17.7%, P = NS) were not different with or without LLI block. CONCLUSION: LLI block, which is more difficult to achieve in patients with a longer VOM, was achievable in 65% of patients with NPAF by linear ablation along the VOM and additional inside CS ablation, but did not affect the short-term clinical outcome.

Defibillator electrogram T wave alternans as a predictor of spontaneous ventricular tachyarrhythmias in defibrillator recipients.

BACKGROUND: Although T wave alternans (TWA) and the T wave peak-to-end (Tpte) interval are associated with vulnerability to ventricular tachyarrhythmia (VT), no previous reports have demonstrated that TWA immediately precedes spontaneous VT in the human ambulatory setting. METHODS AND RESULTS: Stored electrograms from the implantable cardioverter defibrillators (ICD) of 74 patients (59 males, 55.3+/-12.2 years) were analyzed. TWA (DeltaT amplitude), Tpte interval, QT interval, and RR intervals were measured from magnified digital images immediately before spontaneous VT (VT(Clinical); n=73), or immediately after ICD shocks during artificially-induced VT (VT(Induced); n=74) or inappropriate shocks (Shock(Inapp); n=6). (1) TWA was significantly greater in VT(Clinical) than VT(Induced) (P<0.01) or Shock(Inapp) (P<0.001), but Tpte was not (P=NS). (2) In the VT(Clinical) group, TWA was significantly greater in patients with ischemic VT than in those with non-ischemic cardiomyopathy or idiopathic VF (P<0.05). (3) In the same patient, the TWA for VT(Clinical) was significantly greater than that for VT(Induced) (P<0.01). CONCLUSION: TWA measured from ICD electrograms is significantly greater immediately before spontaneous VT than immediately after inappropriate shocks or shocks during induced VT. These findings indicate that repolarization alternans plays an important role in the induction of VT in humans.