Cooled ablation reduces pulmonary vein isolation time: results of a prospective randomised trial.

BACKGROUND: Currently, selection of the ablation catheter for pulmonary vein (PV) isolation is a matter of choice. OBJECTIVE: To evaluate the efficiency of cooled ablation for PV isolation. METHODS: A prospective randomised trial was carried out comparing the time required to disconnect each targeted PV using cooled ablation (open irrigation at 15 ml/min, group A) or standard temperature-controlled 4 mm tip catheter ablation (group B). The ablation parameter limit settings were 45 degrees C, 35 (5) W in group A, and 55 degrees C, 35 (5) W in group B. RESULTS: Thirty-six patients referred for a first atrial fibrillation (AF) ablation procedure were randomised to group A or group B (18 patients in each group). There were no significant differences in baseline characteristics between the groups. Bidirectional block was achieved in 61/61 PVs from group A (100%) and 59/61 PVs from group B (97%); p = NS. Time to PV disconnection was significantly shorter in group A than in group B (median (25th-75th centiles) 14 (5-28) min vs 19 (14-32) min, respectively; p = 0.003). Five asymptomatic PV stenoses were identified by MRI, all in group B (p = 0.05). After 1-year minimum follow-up, AF recurrences were less frequently documented in patients treated with cooled ablation (6% vs 33%; p = 0.05). CONCLUSION: Cooled ablation is more efficient than standard ablation in achieving PV isolation. Results obtained from this study also suggest a potential benefit of clinical efficacy and safety from cooled ablation, which should be further evaluated in larger clinical trials.

Vasoespasmo tras quimioterapia con 5-fluorouracilo / Coronary vasospasm after 5-fluorouracil chemotherapy

No disponible

Benefit of pacing and beta-blockers in idiopathic repetitive polymorphic ventricular tachycardia.

An 18-year-old woman presented with recurrent exercise-induced syncopal episodes and severe systolic dysfunction. ECG monitoring disclosed repetitive polymorphic ventricular complexes, paroxysms of bidirectional ventricular tachycardia, and nonsustained bursts of slow polymorphic ventricular tachycardia that increased in length and rate during exercise. Ventricular arrhythmias were refractory to medical treatment, which included verapamil and beta-blockers. Addition of permanent atrial pacing to beta-blocker therapy suppressed the arrhythmias and reversed systolic impairment in the following months.

Rate-dependent conduction block of the crista terminalis in patients with typical atrial flutter: influence on evaluation of cavotricuspid isthmus conduction block.

BACKGROUND: The crista terminalis (CT) has been identified as the posterior boundary of typical atrial flutter (AFL) in the lateral wall (LW) of the right atrium (RA). To study conduction properties across the CT, rapid pacing was performed at both sides of the CT after bidirectional conduction block was achieved in the cavotricuspid isthmus by radiofrequency catheter ablation. METHODS AND RESULTS: In 22 patients (aged 61+/-7 years) with AFL (cycle length, 234+/-23 ms), CT was identified during AFL by double electrograms recorded between the LW and posterior wall (PW). After the ablation procedure, decremental pacing trains were delivered from 600 ms to 2-to-1 local capture at the LW and PW or coronary sinus ostium (CSO). At least 5 bipolar electrograms were recorded along the CT from the high to the low atrium next to the inferior vena cava. No double electrograms were recorded during sinus rhythm in that area. Complete transversal conduction block all along the CT (detected by the appearance of double electrograms at all recording sites and craniocaudal activation sequence on the side opposite to the pacing site) was observed in all patients during pacing from the PW or CSO (cycle length, 334+/-136 ms), but it was fixed in only 4 patients. During pacing from the LW, complete block appeared at a shorter pacing cycle length (281+/-125 ms; P<0.01) and was fixed in 2 patients. In 3 patients, complete block was not achieved. CONCLUSIONS: These data suggest the presence of rate-dependent transversal conduction block at the crista terminalis in patients with typical AFL. Block is usually observed at longer pacing cycle lengths with PW pacing than with LW pacing. This difference may be a critical determinant of the counterclockwise rotation of typical AFL.

Regional diastolic function in ischaemic heart disease using pulsed wave Doppler tissue imaging.

AIMS: The aim of this study was to determine the utility of pulsed wave Doppler tissue imaging in the evaluation of regional left ventricular diastolic function in patients with ischaemic heart disease. METHODS AND RESULTS: In 30 normal subjects and 43 patients with ischaemic heart disease, Doppler tissue imaging was performed in each of the 16 segments of the myocardium. The following diastolic pulsed wave Doppler tissue imaging parameters were obtained for each segment: (1) regional early diastolic peak velocity (regional e wave cm.s-1); (2) regional late diastolic peak velocity (regional a wave cm.s-1); (3) regional diastolic e/a velocity ratio; and (4) the regional isovolumic relaxation time, defined as the time interval from the second heart sound to the onset of the diastolic E wave. In patients with ischaemic heart disease, each of these parameters was evaluated and compared in ischaemic and normally perfused segments, based on the presence or absence of obstructive lesions of the supplying coronary artery. In patients with coronary artery disease, several differences were observed between diseased and normal wall segments: the mean segmental peak early diastolic velocity (e wave) was reduced (mean +/- SD: 6.4 +/- 2.1 cm.s-1 vs 8.5 +/- 2.8 cm.s-1; P < 0.01); the e/a diastolic velocity ratio was decreased (0.95 +/- 0.3 vs 1.5 +/- 0.6, respectively; P < 0.01) and the regional isovolumic relaxation time was prolonged (104 +/- 36.7 ms vs 69.6 +/- 30 ms; P < 0.01. No differences were observed in any of these parameters between the normally perfused segments of ischaemic patients and normal subjects. Patients with a normal transmitral diastolic Doppler inflow pattern had a mean of 3.7 +/- 2.7 myocardial segments with a local e/a pulsed wave Doppler tissue imaging velocity ratio < 1, fewer than those with an inverted diastolic transmitral Doppler inflow pattern (10.3 +/- 3 segments; P < 0.001). Overall sensitivity and specificity for an inverted local e/a ratio and a local isovolumetric relaxation time > or = 85 ms were of 62% and 72% and 69% and 80%, respectively. CONCLUSION: Regional diastolic wall motion is impaired at baseline in ischaemic myocardial segments, even when systolic contraction is preserved. Pulsed wave Doppler tissue imaging is a useful non-invasive technique which allows the assessment of regional diastolic performance and dynamics of the left ventricular myocardium. Further studies are required to define this role in the evaluation of coronary heart disease.

[Radiofrequency ablation of ventricular tachycardia in patients with ischemic cardiopathy]. / Ablación de taquicardia ventricular mediante radiofrecuencia en pacientes con cardiopatía isquémica.

PURPOSE: We analyze the efficacy of radiofrequency catheter ablation and the clinical significance of inducible ventricular tachycardia that had never been documented before (non clinical ventricular tachycardia) in patients with ventricular tachycardia and coronary artery disease. METHODS: Thirty-four patients (30 men, aged 61 +/- 10 years, left ventricular ejection fraction 31 +/- 10%) with coronary artery disease and documented clinical ventricular tachycardia underwent radiofrequency ablation. Thirty-four clinical ventricular tachycardia and 11 non clinical ventricular tachycardia were treated with radiofrequency. Initial therapeutic success was considered when none of the ventricular tachycardia treated with radiofrequency could no longer be induced at the last stimulation protocol before discharge. RESULTS: Clinical ventricular tachycardia was successfully ablated in 23 patients (68%). Initial therapeutic success was obtained in 21 patients (62%). In 6 of them, 7 non clinical ventricular tachycardia poor tolerated were also induced. During a mean follow-up of 26 +/- 15 months ventricular tachycardia recurred in 6 patients (29%). Five of the 6 patients who recurred were discharged with no inducible non clinical ventricular tachycardia. Three patients died during the follow-up. Two of them from heart failure (one with previous recurrence) and the other suddenly with documented asystole after loss of consciousness without previous recurrence. CONCLUSIONS: In our series of patients with ventricular tachycardia and coronary artery disease selected for radiofrequency ablation, acute success was obtained in 62%. After a mean follow-up of 2 years, 44% of all the patients were free from ventricular tachycardia. Although the possibility of ventricular tachycardia recurrence is high (29%), the recurrence rate is not increased by the inducibility of non clinical ventricular tachycardia.

Efficacy of invasive strategy for the management of acute myocardial infarction complicated by cardiogenic shock.

This retrospective study evaluates the influence of an invasive strategy of urgent coronary revascularization on the in-hospital mortality of patients with acute myocardial infarction (AMI) complicated early by cardiogenic shock. Among 1,981 patients with AMI admitted to our institution from 1994 to 1997, 162 patients (8.2%) developed cardiogenic shock unrelated to mechanical complications. The strategy of management was considered invasive if an urgent coronary angiography was indicated within 24 hours of symptom onset. Every other strategy was considered conservative. Fifty-seven patients who developed the shock late or after a revascularization procedure, or who died on admission, were excluded. The strategy was invasive in 73 patients (70%). Five of them died before angiography could be performed and 65 underwent angioplasty (success rate 72%). By univariate analysis the invasive strategy was associated with a lower mortality than conservative strategy (71% vs 91%, p = 0.03), but this association disappeared after adjustment for baseline characteristics. Older age, nonsmoking, and previous ischemic heart disease were independent predictors of mortality. In conclusion, we have failed to demonstrate that a strategy of urgent coronary revascularization within 24 hours of symptom onset for patients with AMI complicated by cardiogenic shock is independently associated with a lower in-hospital mortality. This strategy was limited by the high mortality within 1 hour of admission in patients with cardiogenic shock, the modest success rate of angioplasty in this setting, and the powerful influence of some adverse baseline characteristics on prognosis.

Primary angioplasty versus systemic thrombolysis in anterior myocardial infarction.

OBJECTIVES: This study compares the efficacy of primary angioplasty and systemic thrombolysis with t-PA in reducing the in-hospital mortality of patients with anterior AMI. BACKGROUND: Controversy still exists about the relative benefit of primary angioplasty over thrombolysis as treatment for AMI. METHODS: Two-hundred and twenty patients with anterior AMI were randomly assigned in our institution to primary angioplasty (109 patients) or systemic thrombolysis with accelerated t-PA (111 patients) within the first five hours from the onset of symptoms. RESULTS: Baseline characteristics were similar in both groups. Primary angioplasty was independently associated with a lower in-hospital mortality (2.8% vs. 10.8%, p = 0.02, adjusted odds ratio 0.23, 95% confidence interval 0.06 to 0.85). During hospitalization, patients treated by angioplasty had a lower frequency of postinfarction angina or positive stress test (11.9% vs. 25.2%, p = 0.01) and less frequently underwent percutaneous or surgical revascularization after the initial treatment (22.0% vs. 47.7%, p < 0.001) than did patients treated by t-PA. At six month follow-up, patients treated by angioplasty had a lower cumulative rate of death (4.6% vs. 11.7%, p = 0.05) and revascularization (31.2% vs. 55.9%, p < 0.001) than those treated by t-PA. CONCLUSIONS: In centers with an experienced and readily available interventional team, primary angioplasty is superior to t-PA for the treatment of anterior AMI.

Role of transesophageal echocardiography in the assessment of patients with blunt chest trauma: correlation of echocardiographic findings with the electrocardiogram and creatine kinase monoclonal antibody measurements.

OBJECTIVES: This study was designed to evaluate the usefulness of transesophogeal echocardiography (TEE) for detecting cardiac damage after blunt chest trauma (BCT). BACKGROUND: Multiple methods have been used to detect cardiac damage after a BCT, but none has been demonstrated to be sensitive, specific, and feasible enough. METHODS: This multicenter prospective trial was designed to evaluate the usefulness of TEE in the assessment of patients with BCT and to compare the TEE findings with those provided by the electrocardiogram (ECG) and cardiac isoenzymes assay. One hundred seventeen consecutive patients with a significant BCT were enrolled. A TEE was performed in each patient. Serial ECGs and plasma profiles of creatine kinase (CK) and CK-monoclonal antibody (MB) were obtained. RESULTS: Sixty-six (56%) patients had pathologic findings in the TEE attributed to the BCT (group A). In the remaining 51 (44%) patients the TEE was normal (group B). An abnormal ECG was more frequent in group A (59% vs 24%; p < 0.001), and the serum CK-MB peak level was also higher in group A (174 +/- 30 U/L vs 93 +/- 21 U/L; p = 0.05). Relative to pathologic TEE findings, the sensitivity and specificity of an abnormal ECG were 59% and 73% and of high CK-MB with CK-MB/CK > 5% were 64% and 52%, respectively. CONCLUSIONS: We conclude that TEE can be routinely and safely performed for diagnosing cardiac injuries after a BCT and plays an important role in the evaluation and treatment of these patients. EGG and CK-MB assay are not good methods for detecting cardiac damage in this setting.

Dissection of the aortic sinus of Valsalva complicating coronary catheterization: cause, mechanism, evolution, and management.

We have rarely observed the appearance of a dissection of the aortic sinus of Valsalva during catheterizations of the related coronary artery. The aim of this study is to describe the cause, mechanism, and evolution of this complication, which have implications for the management of the patient. According to our experience (one case out of 12,546 diagnostic and three cases out of 4,970 angioplasty procedures performed during the last 6 years), the dissection of the sinus of Valsalva always results from the retrograde extension of a dissection of the right coronary artery. It usually remains localized, but it may quickly involve the entire aorta. Contrast injections and balloon inflations promote its propagation, so these procedures should be avoided if possible. Instead of angiography, transesophageal echocardiogram is a safe and accurate method for studying its extension and as a follow-up method. The sinus of Valsalva dissections that remain localized during catheterization tend to spontaneously resolve in the first month.

Influence of collateral circulation on in-hospital death from anterior acute myocardial infarction.

OBJECTIVES: Our purpose was to study whether the in-hospital prognosis of anterior acute myocardial infarction (AMI) is influenced by preexistent collateral circulation to the infarct-related artery. BACKGROUND: Collateral circulation exerts beneficial influences on the clinical course after AMI, but demonstration of improved survival is lacking. METHODS: We studied 238 consecutive patients with anterior AMI treated by primary angioplasty within the first 6 h of the onset of symptoms. Fifty-eight patients with basal Thrombolysis in Myocardial Infarction (TIMI) flow >1 in the infarct-related artery or with inadequate documentation of collateral circulation were excluded. Collateral channels to the infarct-related artery before angioplasty were angiographically assessed, establishing two groups: 115 patients (64%) without collateral vessels (group A) and 65 patients (36%) with collateral vessels (group B). RESULTS: There were no differences in baseline characteristics between groups A and B, except for the greater prevalence of previous angina in group B (15% vs. 34%, p = 0.003). During the hospital stay, 26 patients (23%) in group A and 5 (8%) in group B died (p = 0.01). Cardiogenic shock accounted for 74% of deaths. Cardiogenic shock developed in 30 patients (26%) in group A and in 4 (6%) in group B (p = 0.001). The absence of collateral circulation appeared to be an independent predictor of in-hospital death (odds ratio 3.4, 95% confidence interval 1.2 to 9.6, p = 0.02) and cardiogenic shock (odds ratio 5.6, 95% confidence interval 1.9 to 17, p = 0.002). CONCLUSIONS: Preexistent collateral circulation decreases in-hospital death from anterior AMI by reducing the incidence of cardiogenic shock.