Propafenone added to ibutilide increases conversion rates of persistent atrial fibrillation.

OBJECTIVE: To assess the effectiveness and safety of pharmacological conversion of persistent atrial fibrillation (AF) with a combined propafenone plus ibutilide regimen. METHODS AND RESULTS: 100 consecutive patients (66 men, mean (SD) age 65 (10) years) with persistent AF (mean (SD) duration 99 (92) days) admitted for elective pharmacological cardioversion were randomly assigned to treatment with either intravenous ibutilide (1 mg plus an additional 1 mg, if required; n = 51) or oral propafenone (600 mg) plus intravenous ibutilide at the same dose (n = 49). Success rates were 41.1% (21 of 51 patients) for ibutilide alone and 71.4% (35 of 49 patients) for propafenone plus ibutilide (p = 0.0044). However, cardioversion occurred earlier in the ibutilide alone group (55 (20) minutes) compared with the combination group (81 (32) minutes, p = 0.0019). A comparable increase in the QTc interval was observed in both groups but one case of sustained torsade de pointes, requiring electrical cardioversion, was observed in the propafenone plus ibutilide group. No other complications were noted during the hospitalisation period. CONCLUSION: Concurrent administration of propafenone plus ibutilide for pharmacological cardioversion of persistent AF is safe and more effective than ibutilide alone.

In vivo validation of a novel semi-automated method for border detection in intravascular ultrasound images.

The aim of this work was to evaluate a new semi-automated intravascular ultrasound (IVUS) border detection method. The method was used to identify the lumen and the external elastic membrane or the borders of stents in 80 IVUS images, randomly selected from 10 consecutive human coronary arteries. These semi-automated results were compared with observations of two experts. Several indices in each case were obtained in order fully to evaluate the method. The time required for identification of the borders was also recorded. The interobserver variability of the method ranged from 1.21% to 5.61%, the correlation coefficient from 0.98 to 0.99, the slope was close to unity (0.94-1.03), the y intercept close to zero and the Williams index value was close to unity (range 0.67-0.91). The time (mean+/-SD) required for the method to identify the borders of the different vessel layers for the whole IVUS sequence was 5.2+/-0.2 min. The results demonstrate that the method is reliable and capable of identifying rapidly and accurately the different vessel layers depicted in IVUS images.

Treatment of acute lower limb ischemia following the use of the Duett sealing device: report of three cases and review of the literature.

Three cases of local thrombolysis in the treatment of acute lower limb ischemia complicating the utilization of the Duett sealing device are presented. Routine usage of several vascular closure devices after cardiac catheterization and percutaneous coronary intervention (PCI) has been adopted in our institution during the last 3 years (September 1999 to April 2003). The Duett closure device has been used in 420 patients (post-coronary angiography, 359; post-PCI, 61). Three patients (0.7%) demonstrated acute leg ischemia used by inadvertent intravascular administration of the sealing material related to this device. All three were treated successfully by catheter-directed local thromolysis (tissue plasminogen activator 5 mg bolus followed initially by 1 mg/hr and consequently by 0.5-1.0 mg/hr depending upon the development of significant hematoma and lasting for 24 hr). In conclusion, interventional treatment using local thrombolysis should be the first-line treatment in acute lower limb ischemia complicating the utilization of the Duett sealing device.

Haemodynamic and catecholamine response to simulated ventricular tachycardia in man: effect of baseline left ventricular function.

OBJECTIVE: To examine the effects of baseline left ventricular function on the haemodynamic and catecholamine responses to ventricular tachycardia. DESIGN: Experimental cohort study. SETTING: Cardiac catheterisation laboratory in tertiary referral centre. SUBJECTS: 24 patients (19 male, 5 female; mean (SD) age, 59 (10) years) without coronary artery disease, divided into two groups with normal or impaired left ventricular function: group A, ejection fraction > 65% (n = 10); group B, ejection fraction < 45% (n = 14). Other medical and demographic factors were similar in the two groups. INTERVENTIONS: Ventricular tachycardia was simulated with rapid pacing at 150 beats/min for 10 minutes. MAIN OUTCOME MEASURES: Arterial blood pressure; venous plasma catecholamine concentrations. RESULTS: During rapid pacing, blood pressure was lower in group B (with impaired left ventricular function) than in group A: systolic blood pressure, 102 (11) v 115 (9) mm Hg (p = 0.005); mean blood pressure, 79 (6) v 85 (6) mm Hg (p = 0.02). The ejection fraction correlated with the lowest systolic blood pressure (r = 0.64, p = 0.0006). Although the rise in adrenaline was comparable between the two groups, the rise in noradrenaline was more pronounced (p < 0.05) in patients in group B. CONCLUSION: At low rates and in selected patients, the underlying state of left ventricular function affects haemodynamic tolerance of ventricular tachycardia. Patients with impaired left ventricular function have a lower blood pressure during ventricular tachycardia, despite an exaggerated noradrenaline release.

Effects of delayed (24 h postintervention) beta-irradiation therapy after coronary angioplasty and stenting in de novo native coronary artery lesions; Results of a randomized clinical and intravascular ultrasound study.

BACKGROUND: The effects of brachytherapy performed 24 h postintervention in de novo native coronary artery lesions. METHODS AND RESULTS: Thirty-nine patients with 39 de novo coronary artery lesions were randomised to prompt (immediately after intervention, n=21) or delayed (24 h later, n=18) beta brachytherapy ((90)Sr/(90)Y) after been successfully revascularized with stenting. Clinical follow-up data up to 21 months (median time) were compared. After irradiation and at 6-month follow-up, paired volumetric analysis of the stented segment and the 5-mm proximal and distal reference segments was performed; this included measurements of the external elastic membrane, lumen, plaque, and media (external elastic membrane minus lumen), stent and intima hyperplasia (stent minus lumen). Baseline clinical and angiographic characteristics were similar in the two groups. Postintervention measurements of stent, lumen, and intima hyperplasia volumes as well as postintervention minimum lumen cross-sectional areas were not different. In the stented segments and in the segments 5 mm proximal and distal to the stent, similar changes of all IVUS measurements were measured in the two patient groups, but in the lumen volume at the proximal stent edge of patients irradiated 24 h postinjury. At 21 months median follow-up time, target lesion revascularization (TLR) was performed in 8 patients (38%) in the prompt irradiation group compared with 3 (17%) in the delayed (P=.17). CONCLUSION: Beta irradiation is similarly effective whether performed immediately after percutaneous coronary intervention or 24 h later.

External beam irradiation in angioplasted arteries of hypercholesterolemic rabbits. The dose and time effect.

PURPOSE: To study the dose and time effect of external beam irradiation on the morphometry of both angioplasted and nonangioplasted arteries in a hypercholesterolemic rabbit model. METHODS AND MATERIALS: Eight groups of rabbit femoral arteries were studied: arteries (a) with no intervention, (b) irradiated with a 12-Gy 6 MV X-ray dose, (c) with a 18-Gy, (d) treated with balloon angioplasty, (e) dosed with 12-Gy half an hour post-angioplasty, (f) dosed with 18-Gy half an hour post-angioplasty, (g) dosed with 12-Gy 48 h post angioplasty, (g) dosed with 18-Gy 48 h post angioplasty. RESULTS: External irradiation at either 12 or 18 Gy was not found to change vessel morphometry in noninjured arteries. The 12-Gy dose given soon after angioplasty further increased percentage stenosis (63% on the average), despite the preservation of the lumen cross-sectional area. Positive remodeling was not observed in arteries given 18-Gy half an hour post angioplasty to counterbalance the increased neointimal formation. Therefore, this treatment resulted in a drastic reduction in lumen area and in enhancement of percentage stenosis (84% on the average). On the contrary, the delayed irradiation of the angioplasted arteries at either 12 or 18 Gy was not found to influence any of the studied morphometric parameters 5 weeks after angioplasty. CONCLUSIONS: Uniform external beam irradiation up to 18 Gy was well tolerated by intact femoral arteries. Prompt 12- or 18-Gy irradiations accentuated percentage stenosis. However the lumen cross-sectional area was preserved only at the lower dose point. Delayed irradiation at any dose did not influence the restenosis process.

Platelet hyperaggregability to platelet activating factor (PAF) in non-ST elevation acute coronary syndromes.

It is known that myocardial ischaemia increases platelet aggregatory response to various agonists, ex vivo. We investigated the platelet aggregatory response to platelet activating factor (PAF), ex vivo, in patients with non-ST elevation acute coronary syndromes and determined the specificity and sensitivity of this response. Thirty-two consecutive patients with non-ST elevation acute coronary syndromes and 20 healthy volunteers were studied. Platelet aggregation in platelet-rich plasma was studied on the day of admission. The maximal aggregation achieved within 2 min after the addition of PAF (100 nM) was expressed as a percentage of 100% light transmission. PAF EC50 values were defined as the concentration that induces 50% of maximal aggregation. The PAF EC50 values of the non-ST elevation acute coronary syndromes patients were significantly lower compared to those of the controls (p < 0.0001). The maximal percentage of aggregation was also significantly higher (p < 0.0005). Ninety-one per cent of the patients were correctly classified using PAF EC50 values (specificity 90.0% and sensitivity 91.2%); the corresponding results using the maximal percentage of aggregation were 80% (specificity 70.0% and sensitivity 87.5%). The estimated values used as thresholds were 22.47 nM and 17.97 for the PAF EC50 and the maximal percentage of aggregation, respectively. The results of the present study suggest that platelet hyperaggregability to PAF, ex vivo, in non-ST elevation acute coronary syndromes is characterised by a high specificity and sensitivity, and thus it may represent a mechanism contributing to the pathophysiology of acute coronary syndromes.

Serum lipoprotein(a) concentrations and apolipoprotein(a) isoforms: association with the severity of clinical presentation in patients with coronary heart disease.

OBJECTIVE: The aim of this study was to investigate the possible associations between lipoprotein(a) [Lp(a)] concentrations or apolipoprotein(a) isoforms and the mode of clinical presentation of coronary heart disease (CHD) (acute thrombotic event or not). METHODS: A total of 131 CHD patients and 71 age- and gender-matched individuals without known CAD (free of symptoms of heart disease) were enrolled in the study. CHD patients were classified into patients with a history of an acute coronary syndrome (ACS, n=94) and patients with stable angina (SA, n=37). Lp(a) levels were measured with an ELISA method, whereas apolipoprotein(a) isoform analysis was performed (in all patients and 33 controls) by electrophoresis in 1.5% SDS-agarose gels followed by immunoblotting. Isoform size was expressed as the number of kringle 4 (K4) repeats. RESULTS: ACS patients had higher Lp(a) plasma levels 121.9 (0.8-84.1) mg/dl] and a greater proportion of elevated (> or = 30 mg/dl) Lp(a) concentrations (25.5%) compared with SA patients [9.2 (0.8-50.5) mg/dl, P < 0.01 and 10.8%, P < 0.05] and controls [8.0 (0.8-55.0) mg/dl, P < 0.01 and 11.2%, P < 0.05], while there were no differences between SA patients and controls. The median apolipoprotein(a)-isoform size was 26 K4. In 17 (10%) patients we could not detect any apolipoprotein(a) isoform bands by immunoblotting. ACS patients had a higher proportion of isoforms < 26 K4 (low molecular weight) than SA patients (56/85 vs. 12/33, P < 0.005) and controls (10/29, P < 0.005). CONCLUSIONS: CAD patients with a history of ACS have higher Lp(a) plasma levels and a significantly higher proportion of low molecular weight apolipoprotein(a) isoforms compared with patients with SA or to controls.

[The effect of volume status of the right-left shunt in a patient with a patent foramen ovale]. / Einfluss des Volumenstatus auf den Rechts-links-Shunt bei einem Patienten mit funktionell offenem Foramen ovale.

This is a description of the anaesthetic management of a patient with a flow patent foramen ovale undergoing intramedullary nailing of the femur. In order to detect the flow patent foramen ovale, we used transoesophageal echocardiography. During the ventilation maneuver with positive airway pressure of 20 cmH2O, a right-to-left interatrial shunt was observed. After the administration of 500 ml hydroxy-starch solution (6%) intravenously, detection of the right-to-left shunt flow was no longer possible. This case report shows that the volume status in a patient with a patent foramen ovale could influence the right to left interatrial shunt during general anaesthesia.

Relatively low red cell folate levels and acute coronary syndromes.

BACKGROUND: Low folate levels are related to increased risk for coronary artery disease in humans, while experimental work has shown that folate deficiency is thrombogenic. We hypothesized that relatively low folate levels are related to the development of acute coronary syndromes in patients with previously stable coronary artery disease. METHODS: One hundred and forty-one men were studied: 53 consecutive patients with acute coronary syndromes, 41 with stable coronary artery disease and 47 control participants. Known clinical and lipid risk factors were identified in all subjects and in addition plasma B12, plasma and red cell folate levels were measured. RESULTS: Red cell folate levels were significantly lower in patients with acute coronary syndromes (510+/-178 nmol/l) than in both stable coronary artery disease patients (638+/-264 nmol/l, P< 0.005) and controls (615+/-193 nmol/l, P< 0.05 respectively). Plasma folate and B12 levels were similar in all three groups. Multiple logistic regression analysis identified red cell folate levels as the only independent predictor of acute coronary events in the whole population of patients with known coronary artery disease and in the subgroup of non-smokers (P=0.010 and P=0.031). CONCLUSIONS: The present study suggests that relatively low red cell folate levels are associated with acute coronary syndromes and are an independent predictor of acute coronary events.

Vibrational angioplasty and hydrophilic guidewires in the treatment of chronic total coronary occlusions.

PURPOSE: To study the efficacy and safety of vibrational angioplasty versus hydrophilic guidewires for recanalizing chronic total occlusions (CTOs) of the coronary arteries. METHODS: In a retrospective study, 99 patients with old (>3 months) CTOs resistant to conventional techniques were treated either with vibrational angioplasty (group A, n = 72) or 0.014-inch hydrophilic guidewires (group B, n = 27). The selection of the technique (vibrational angioplasty or hydrophylic guidewires) was dependent only upon device availability. A variety of guidewires were employed in conjunction with vibrational angioplasty. RESULTS: The crossing success rates in groups A and B were 86.1% (62/72) and 55.5% (15/27) (p < 0.05), with final procedural success rates of 75% (54/72) and 44.4% (12/27) (p < 0.01), respectively. The main reasons for failure were inability to cross the lesion with a guidewire (10/18 in group A and 12/15 in group B) and large dissections resulting in vessel closure (2/18 in group A and 2/15 in group B). Three major complications were seen, 2 in group A and 1 in group B. Three vessel perforations were reported in group A. Both techniques needed prolonged fluoroscopy times. CONCLUSIONS: Vibrational angioplasty was more successful in treating CTOs compared to hydrophilic guidewires and had similar complication rates (most without clinical sequelae).

Ventricular pre-excitation in the general population: a study on the mode of presentation and clinical course.

OBJECTIVE: To describe the mode of presentation and the clinical course of patients with ventricular pre-excitation (Wolff-Parkinson-White (WPW) syndrome), with special emphasis on asymptomatic cases in the general population. METHODS: Over an eight year period (1990-97) a prospective population based survey of cases with WPW pattern was conducted in a defined population in north west Greece (340 000 inhabitants). ECGs with WPW pattern were obtained from a widespread pool of ECGs within the health system. RESULTS: During the study period, 157 cases with WPW pattern were identified (49 female, 108 male). Ages ranged from infants to 84 years, mean (SD) 49.1 (21.0) years in female and 39.6 (20.6) years in male subjects (p < 0.01); 78 (49%) had no history of syndrome related symptoms. Asymptomatic subjects (n = 77; 24 female, 53 male) were older than symptomatic subjects (mean age 46.7 (21.0) v 38.5 (20.6) years, p < 0.03). Documented supraventricular tachycardia was recorded in 27 patients (17%) and atrial fibrillation in 12 (8%) (mean age at first episode 31.2 (18.3) and 51.6 (20.7) years, respectively, p < 0.01). During follow up (mean 55 months) no case of sudden death occurred. Three asymptomatic subjects reported episodes of brief palpitation. CONCLUSIONS: WPW pattern is more common, and diagnosed at a younger age, in men than in women. About half the patients with WPW pattern on ECG are asymptomatic at diagnosis and tend to remain so thereafter. No sudden cardiac death occurred during the study period.

External beam irradiation following balloon angioplasty in an atherosclerotic rabbit model.

PURPOSE: To study the effect of external beam irradiation on the morphometry of both angioplasted and nonangioplasted arteries in a hypercholesterolemic rabbit model. METHODS AND MATERIALS: Four groups of rabbit femoral arteries were studied: arteries (a) with no intervention, (b) irradiated with a 12-Gy x-ray dose, (c) treated with balloon angioplasty, and (d) dosed with 12 Gy 30 min after balloon angioplasty. RESULTS: External irradiation did not change vessel morphometry in nonangioplasted arteries. On the contrary, it induced neointimal formation and decreased luminal area, without causing any vessel remodeling in arteries treated with balloon angioplasty. CONCLUSION: External irradiation at 12 Gy given 30 min after angioplasty in the studied model accentuated the neointimal response to vascular injury, without causing any vessel remodeling.

An epidemiological study of symptomatic paroxysmal atrial fibrillation in northwest Greece.

AIM: Although atrial fibrillation (AF) is the most commonly sustained arrhythmia, information about its incidence in the general population is sparse. Even more sparse is information on an important variety of AF, paroxysmal AF. The aim of this study is to assess the frequency of new cases of symptomatic paroxysmal AF per year ('incidence') in a general unselected population and to compare other epidemiological features with chronic AF patients. METHODS AND RESULTS: Over a 4 year period, we conducted a prospective, population-based survey of cases of AF in a defined geographical area with a known population size stratified for age and sex. Sources of identification were the two hospitals which serve the area and all the primary care settings. Patients with AF of less than 7 days duration were characterized as paroxysmal AF and all others as chronic AF. During the study period we identified 1551 patients with chronic AF (51.7% male, mean age 71 +/- 10.4 years and 48.3% females, mean age 73.1 +/- 10.8 years) and 443 patients with paroxysmal AF (59.6% male, mean age 59.6 +/- 13.3 years and 40.4% female, mean age 65.2 +/- 10.1 years). There was no underlying cardiovascular disease in 15.6% and 32.3% of patients with chronic and paroxysmal AF, respectively. The mean annual occurrence of new cases of paroxysmal AF was 6.2/10,000/year, and was higher (P<0.01) for men (7.2/10,000/year) than for women (5.3/10,000/year). The frequency of new paroxysmal AF cases rises with age, reaching a peak at 70-79 years and then declines. CONCLUSIONS: We conclude that paroxysmal AF is a relatively common arrhythmia, the occurrence of which increases with age and is more frequent in younger men than in women. Patients with chronic AF are older and more often have underlying heart and other disease than patients with paroxysmal AF.