Relationship between cycle length of typical atrial flutter and double potential interval after achievement of complete isthmus block.

BACKGROUND: There is some disagreement concerning the minimal value of the interval between components of double potentials (DPs interval) that allows distinguishing complete and incomplete block in the cavotricuspid isthmus (CTI). OBJECTIVES: To assess clinical utility of the relationship between atrial flutter cycle length (AFL CL) and the DPs interval. METHODS: Ablation of the CTI was performed in 87 patients during AFL (245 ± 40 ms). Subsequently, DPs were recorded during proximal coronary sinus pacing at sites close to a gap in the ablation line and after achievement of complete isthmus block. RESULTS: We noted strong correlation between AFL CL and the DPs interval after achievement of isthmus block (r = 0.73). The mean DPs interval was 95.3 ± 18.3 ms (range 60-136 ms) and 123.3 ± 24.3 ms (range 87-211 ms) during incomplete and complete isthmus block, respectively (P < 0.001). When expressed as a percentage of AFL CL, this interval was 35.7 ± 3.5% AFL CL (range 28-40.2%) and 50.4 ± 6.9% AFL CL (range 39-72%) during incomplete and complete isthmus block, respectively (P < 0.001). A cutoff value of 40% of AFL CL identified CTI block with 96.7% sensitivity and 100% specificity. CONCLUSIONS: The interval between DPs after achievement of block in the CTI correlates with AFL CL. The DPs interval expressed as a percentage of AFL CL allows better distinguishing between complete and incomplete isthmus block compared to standard method based on milliseconds. The DPs interval below 40% of AFL CL indicates sites close to a gap in the ablation line.

Combined subarachnoid and epidural anaesthesia for endoprosthetoplasty of the knee joint.

Background. We investigated the efficacy of combined spinal epidural anaesthesia (CSEB) that combines the main spinal and the supporting epidural anaesthesia for pain treatment after total knee replacement (TKR). Material and methods. Fifty-eight patients scheduled for elective TKR surgery were randomly allocated into two groups: Group I (intraoperative Combined Spinal - Epidural Block) and Group II (intraoperative spinal anaesthesia). Postoperative analgesia was provided with continuous epidural infusion (CEI) of 0.25% bupivacaine + fentanyl solution in Group II and intravenous doses of paracetamol and/or tramadol on patient request in Group I. Results and Discussion. There were no significant changes in intraoperative readings of hemodynamic parameters, respiratory rate and SaO2 in both groups. However systolic arterial blood pressure (SABP), diastolic arterial blood pressure (DABP) and respiratory rate were decreased postoperatively in Group II, while an increase of these parameters in Group I was observed. CEI was well tolerated by all patients and the only reported side effect (skin itching) was of minor clinical concern. We conclude that CSEB provides better pain relief for patients having knee joint replacement what consequently leads to faster knee rehabilitation and therefore eventually decreases the risk of postoperative cardiogenic complications, embolia and phlebothrombosis.

Catheter ablation of atrial fibrillation in patients with hypertrophic cardiomyopathy: atrial fibrillation type determines the success rate.

BACKGROUND: Atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) is generally associated with deterioration of the clinical status, functional capacity, and quality of life. It is also an independent risk factor for stroke and death. Studies evaluating the effectiveness of AF ablation in this cohort are relatively scant, have included relatively few patients, and their results are somewhat conflicting. Thus, the aim of this study was to assess the safety and efficacy of catheter ablation of AF in patients with HCM. METHODS: Thirty patients (10 females; mean age 48.7 ± 11 years) with drug-refractory paroxysmal (n = 14), persistent (n = 7), or long-persistent (> 1 year; n = 9) AF were prospectively recruited into the study. Eleven patients were in New York Heart Association (NYHA) class I, 13 patients were in NYHA class II, and 6 patients were in NYHA class III. Mean atrial volume was 180 ± 47 mL, interventricular septum thickness was 20.5 ± 6.3 mm, and left atrial area was 29.8 ± 6.2 cm2. Ablation protocol was adjusted to the clinical and electrophysiological status of the patients. Pulmonary vein isolation and bidirectional cavo-tricuspid isthmus block were performed in all patients. In addition, left atrial linear lesions were created and complex fragmented atrial potentials were ablated in patients with persistent and long-persistent AF, as well as during repeated procedures. RESULTS: At 12 months, stable sinus rhythm (SR) was present in 16 (53%) patients, significantly more frequently in patients with paroxysmal AF (71% in SR) compared to those with persistent (57.1% in SR) or long-persistent (22% in SR) AF. A significant reduction of AF burden was observed in 85.7% of patients with paroxysmal AF, 71.4% of patients with persistent AF, and 55.5% of patients with long-persistent AF. Single procedure success rate was 33% (10 patients), and repeat ablation procedures were performed in 13 patients. No periprocedural complications occurred. Thromboembolic events were noted in 2 patients with arrhythmia recurrence during the follow-up, including stroke in 1 patient and peripheral embolism in the other patient. In both these patients, heart failure worsening was observed during these events, and anticoagulation was inadequate in one of them. Five of 16 patients in whom stable SR was observed during the follow-up were off antiarrhythmic drug therapy at final evaluation. In the other 6 patients, antiarrhythmic drug therapy was continued due to ventricular arrhythmias. Successfully treated patients more often had paroxysmal AF (successful ablation: paroxysmal AF in 10 of 16 patients; unsuccessful ablation: paroxysmal AF in 4 of 14 patients; p = 0.009) and were younger (45 ± 11.5 years vs. 52.6 ± 9.2 years; p = 0.046). In addition, a trend toward a reduced need for cardioversion at the end of the procedure was also observed in these patients (3 patients in the successful ablation group vs. 8 patients in the unsuccessful ablation group; p = 0.056). In multivariate regression analysis, paroxysmal AF was the only independent predictor of a successful outcome. CONCLUSIONS: Catheter ablation of AF in patients with HCM is an effective and safe therapeutic option, particularly in patients with paroxysmal AF. Effectiveness of ablation is significantly smaller in patients with persistent AF and even more so in those with long-persistent AF. Repeated procedures were often necessary. Continued antiarrhythmic drug therapy is often required due to a significant degree of atrial remodelling.

Late gadolinium enhancement gray zone in patients with hypertrophic cardiomyopathy. Comparison of different gray zone definitions.

To quantify heterogeneous tissue at the periphery of areas of fibrosis (gray zone) in patients with hypertrophic cardiomyopathy (HCM) with the use of two different techniques. Cardiac magnetic resonance with late gadolinium enhancement analysis was performed in 33 patients with HCM. Gray zone was evaluated with the use of two different techniques previously described in patients after myocardial infarction. LGE was present in 25 (78%) patients. There was no significant difference in total LGE mass at two different cut-off values [53.8 g (interquartile range, IQR 43.5-77.8 g) vs. 53.8 g (IQR 37.8-64.5 g), respectively, P = 0.49]. Significant difference in gray zone mass assessed with the use of two techniques was demonstrated (19.1 +/- 7.3 g vs. 50.8 +/- 47.8 g; P = 0.003). There was a strong correlation between total LGE and gray zone mass (r = 0.789, P = 0.0001 for first method and r = 0.951, P < 0.0001 for the second one, respectively). However, significant variability of gray zone mass (and extent expressed as % of left ventricular mass) in patients with similar LGE size/extent was observed. Moreover, LGE mass varied greatly in patients with similar gray zone size. Neither left ventricular mass, nor with maximal wall thickness correlated with extent of gray zone assessed with both methods. The studied techniques provided similar results with regard to total LGE but significant differences were observed in gray zone mass. Two patients may have similar extent (or absolute mass) of LGE, but strikingly discrepant gray zone size.