Should we measure routinely oxidised and atherogenic dense low-density lipoproteins in subjects with type 2 diabetes?

Beyond low-density lipoprotein (LDL)-cholesterol concentrations, in recent years, several clinical studies have shown that both oxidised and small, dense LDL have a strong predictive role for the presence of vascular atherosclerosis. These two lipid parameters seem to have a synergistic impact on cardiovascular risk, with a greater importance in patients at higher-risk, such as those with type-2 diabetes. Increased levels of oxidised and small, dense LDL levels are a feature of diabetic dyslipidaemia, and small, dense LDL have been shown to be a good predictor of future cardiovascular events, at both univariate and multivariate analyses. On the other hand, although the association of oxidised LDL with surrogate markers of atherosclerosis is consistent, the correlation with hard clinical end points seems to be smaller. Yet, measurement of these two lipid parameters has not been widely used in daily practice because of the limited availability of clinical data and methodological problems: lack of availability of easy, cheap and reproducible essays for measurement of oxidised and, particularly, small, dense LDL has reduced their assessment in large clinical end-points trials. However, on the basis of available data, the therapeutic modulation of small, dense LDL is significantly associated with reduced cardiovascular risk, even after adjustment for confounding factors. In conclusion, the routine measurement of oxidised and small, dense LDL in patients with type-2 diabetes cannot be recommended in daily clinical practice so far; yet, their measurement is strongly encouraged to better understand their role on the cardiovascular risk of patients with type-2 diabetes.

The control of dyslipidemia in outpatient clinics in Greece (OLYMPIC) Study.

The objective of this study was to determine the proportion of Greek patients referred to outpatient clinics for dyslipidemia who achieved the low-density lipoprotein cholesterol (LDL-C) goal defined by the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) guidelines, using lifestyle changes, lipid-lowering drug treatment (LLDT), or both. Adult patients with dyslipidemia, who had been receiving a hypolipidemic diet and/or LLDT for at least 3 months were assessed in a multicenter study performed at 66 sites across Greece. Patients were followed up for an additional 3-month treatment period. Lipid levels were recorded at baseline and at the end of the study. The primary endpoint was the proportion of patients achieving their individual LDL-C target at the end of the study, according to their coronary heart disease (CHD) risk status or its equivalents, as defined by the NCEP-ATP III guidelines. Multivariate logistic models were used to identify determinants of undertreatment. The study included 2,660 adults (20-75 years) from 7 regions of Greece. Of the evaluable sample (n = 2,211; men 51%; mean age 62 +/-9 years) 81% were receiving LLDT (96% with statins and 3% with fibrates), 44% had a history of CHD, 61% arterial hypertension, 36% diabetes, and 26% a family history of premature CHD. Overall, 6% were at low CHD risk, 30% at medium CHD risk, and 63% at high CHD risk. At the end of the study, 26% of all patients and 30% of those receiving LLDT achieved the NCEP-specified LDL-C target levels. The percentage of patients at LDL-C goal according to CHD risk status was: low risk 67% (95% CI = 59-75), medium risk 29% (95% CI = 26-33), and high risk 20% (95% CI = 18-22). Statins proved to be more effective than fibrates (p <0.0001). Atorvastatin-treated subjects (n = 1,222, mean dose 19 mg/day) attained the LDL-C target (31% of the cases) at a higher rate than those receiving other LLDT (n = 574, 26% at target, p <0.01) or not receiving drug treatment (n = 415, 8%, p <0.001). This outcome was more evident in the high-CHD risk group (n = 1,402, 26% with atorvastatin vs 16% with other LLDT and 3% not receiving LLDT attained the LDL-C goal, ANOVA, p <0.001). The majority of dyslipidemic patients receiving LLDT, mainly those with high-CHD risk, are not achieving the NCEP LDL-C target. This is mainly explained by inadequate dose titration to ensure target goals are met. Promoting healthy lifestyle and appropriate LLDT (potent statins with sufficient dose titration) must be implemented to ensure that patients attain LDL-C treatment goals and thus benefit from the reduction in individual CHD risk.

Arrhythmia recurrences are rare when the site of radiofrequency ablation of the slow pathway is medial or anterior to the coronary sinus os.

AIMS: The site of successful ablation of the slow atrioventricular (AV) nodal pathway may be located in the posteroseptal or midseptal area. We have previously shown that the site of successful radiofrequency (RF) ablation of the slow pathway, rather than residual slow pathway conduction correlates with AV nodal re-entrant tachycardia (AVNRT) recurrences, with more recurrences noted in inferoposterior (to the coronary sinus os) locations. Accordingly, we have since modified our approach, and in a consecutive series of 105 patients we have performed slow pathway RF ablation exclusively at medial or anterior locations, with the objective of prospectively examining the recurrence rate of AVNRT incurred with this approach. METHODS AND RESULTS: The study included 40 men and 65 women, aged 42 +/- 18 years, having RF ablation for symptomatic AVNRT exclusively in anterior to the coronary sinus os locations. A combined anatomical and electrophysiological approach to slow pathway ablation was employed. This series of patients was compared with the previous series of 55 patients (historical group) with AVNRT undergoing RF ablation at both inferoposterior and anteromedial locations. The mean cycle length of the induced AVNRT was 329 +/- 48 ms. RF ablation was successful in all patients (100%). A mean of 7 +/- 6 lesions were applied. Persistent jump or echo beats were noted in 48 patients (46%). The procedure lasted for 2.1 +/- 1.0 h. Fluoroscopy time was 23 +/- 14 min. Procedures were complicated by heart block in two patients (1.9%). Over 26 +/- 19 months, there has been only one recurrence of AVNRT (1%). The historical group had similar age (37 +/- 18 years), gender (17 men/38 women), AVNRT cycle length (340 +/- 60 ms), number of RF lesions (9 +/- 6), or residual slow pathway conduction (42%), but longer fluoroscopy time (41 +/- 25 min) and procedure duration (4 +/- 1 h), and a significantly higher recurrence rate (seven patients/13%) (P=0.004) at a much shorter follow-up period of 12 +/- 8 months. CONCLUSION: AVNRT recurrences are rare (1%) when slow pathway RF ablation is performed in medial or anterior locations at the tricuspid annulus, rather than in inferoposterior sites, whereby a higher (13%) recurrence rate has been previously noted.

Right ventricular cardiomyopathy in beta-thalassaemia major.

AIMS: To evaluate right ventricular function in patients with beta-thalassaemia major and congestive heart failure. Background In patients with beta-thalassaemia major a high incidence of cardiac involvement still exists despite improved prognosis with chelation therapy. Development of severe right heart failure is common and has been attributed to pulmonary hypertension secondary to lung haemochromatosis. However, the possibility of direct right ventricular myocardial involvement in the absence of significant pulmonary hypertension has not been adequately investigated. METHODS: Twenty-nine consecutively screened patients with beta-thalassaemia major and congestive heart failure were investigated by Doppler echocardiography, right ventricular first-pass radionuclide examination and cardiac catheterization. Haemodynamic data were obtained both before and after volume loading. A control group of 39 patients with beta-thalassaemia major, free from cardiac disease, and matched for age, gender, body surface area and heart rate was used for comparison. A subset of the control thalassaemic group (n=15) underwent both radionuclide and haemodynamic assessment. RESULTS: The majority of patients were on non-optimal chelation therapy. Only two of 29 patients were found to have cor pulmonale. One other patient suffered from constrictive pericarditis. A restrictive filling pattern in both ventricles and left ventricular systolic dysfunction were evident in the other 26 patients. Pulmonary artery pressure (systolic, 33+/-8 vs 27+/-5 mmHg, P<0.05) and pulmonary vascular resistance (114+/-56 vs 65+/-29 dynes. s. cm(-5), P<0.01) were only mildly elevated in the heart failure group. After volume challenge, cardiac output remained unchanged although the increments of ventricular filling pressures were significant (Deltaright atrial: 4.8+/-2.2 mmHg, P<0.05; Deltapulmonary capillary wedge: 5.6+/-2.9 mmHg, P<0.05) and correlated with each other (r=0.69;P<0.001) in heart failure patients, suggesting pericardial constraint and ventricular interaction. In these patients compared with the control thalassaemic group, a lower right ventricular ejection fraction (29%+/-9 vs 59%+/-6, P<0.0001) without correlation with pulmonary artery pressures was found. Haemodynamically significant right ventricular dysfunction defined as mean right atrial pressure >10 mmHg and ratio of mean right atrial-to-capillary wedge pressure >0.8 was evident in 15 of the 26 patients (58%), all with severe symptoms, representing three fourths of the patients in functional class III and IV. Simultaneous pressure recordings in six of these 15 patients showed equalization of ventricular end-diastolic pressures within 5 mmHg. CONCLUSION: The majority of patients with beta-thalassaemia major and severe congestive heart failure demonstrated a unique haemodynamic pattern similar to that described in predominant right ventricular infarction, indicating severe right ventricular cardiomyopathy in addition to left ventricular dysfunction. The incidence of cor pulmonale as a cause of right heart failure seems to be much lower than previously hypothesized.

Radiofrequency ablation in pediatric and adult patients: comparative results.

BACKGROUND: Radiofrequency (RF) catheter ablation has been widely and successfully employed to cure adult and pediatric patients of a variety of arrhythmias. Only limited data exist which compare the results in these two groups. The aim of this study was to compare the efficacy and safety of RF catheter ablation in pediatric versus adult patients performed by an adult electrophysiology (EP) team. METHODS: The study group included 327 consecutive pediatric (n=47) and adult (n=280) patients, aged 7-82 years (mean 40+/-19), with symptomatic tachyarrhythmias, who underwent RF ablation during the last 6 years. All but ten patients underwent a full EP study during the same session. Procedures were performed in all but five patients with use of local anesthesia and deep or light sedation. The left heart was approached with use of transaortic (n=36) or transseptal (n=55) or both (n=6) techniques. RF ablation was performed for manifest or concealed accessory pathways in 132 patients, AV nodal slow pathway in 119, atrial tachycardia in 24, atrial flutter in 15, atrial fibrillation in one, ventricular tachycardia in 29, and AV node/His bundle in 7 patients. RESULTS: RF ablation was successful in 271 (96.8%) patients in the adult group and in all patients (100%) in the pediatric group, with a mean of 15+/-18 (median: 8) vs 12+/-10 (median: 8) RF applications respectively (P=NS). Complications occurred in four patients (1.4%) in the adult group and in one patient (2.1%) in the pediatric group (P=NS). Fluoroscopy time averaged 43+/-40 min vs 39+/-27 min and procedures lasted for 3.0+/-1.9 hours vs 2.8+/-1.4 hours respectively (P=NS). During long-term follow-up of 25+/-19 months, there were 12 (4.4%) recurrences among the adult patients, and three (6.4%) recurrences in children, with nine of them successfully treated with repeat RF ablation. Procedural variables were dependent on the type of arrhythmia ablated, rather than on patient's age. Patients with multiple accessory pathways or atrial flutter required the greatest number of RF applications and the longest fluoroscopy exposure and duration of the procedure; the lowest values of these variables concerned ablation of the slow AV nodal pathway or the AV node/His bundle. CONCLUSION: RF ablation in adult and pediatric patients performed by an adult EP team is equally efficacious and safe offering cure of symptomatic cardiac tachyarrhythmias in both patient populations.

Autonomic patterns preceding and following accelerated idioventricular rhythm in acute myocardial infarction.

INTRODUCTION: We have investigated the potential relationship between cardiac autonomic activity and accelerated idioventricular rhythm (AIVR) in response to reperfusion in the setting of an acute myocardial infarction (AMI) through spectral analysis of heart rate variability (HRV). METHODS AND RESULTS: We studied 16 patients with AMI who developed spontaneous sustained AIVR after initiation of intravenous thrombolysis. Sympathovagal interactions were evaluated by analysis of the low- (LF) and high-frequency (HF) spectral components of HRV for each 5-min interval over the 30-min periods preceding and following AIVR. The occurrence of AIVR was related to the ST-segment elevation resolution and the angiographic evidence of restored coronary flow to assess timely reperfusion and sustained coronary artery patency. The analysis of spectral components over time revealed combined responses of both autonomic limbs preceding and following AIVR, which were not followed by corresponding changes in heart rate. Ten minutes before AIVR, there was a characteristic continuous increase in LF, in the setting of a concomitant withdrawal of HF, suggestive of a progressive sympathetic predominance. After the end of AIVR, the opposite pattern was found with an increased HF and decreased LF, indicative of parasympathetic rebound overactivity. All patients showed signs of fast reperfusion and complete restoration of coronary flow. CONCLUSION: Our results indicate that reperfusion-induced AIVR is modulated by sympathetic stimulatory effects, whereas a counterregulatory vagal response seems to exert a profound effect upon its suppression. Clinically, the occurrence of early sustained AIVR appears to offer reliable information about both timely reperfusion and sustained and effective coronary artery patency.

The prognostic significance of atrial arrhythmias recorded early after cardioversion for atrial fibrillation.

In a substantial number of patients, AF recurs after successful electrical cardioversion. The purpose of this study was to investigate if the atrial arrhythmias recorded immediately after cardioversion are associated with the risk of recurrence of the arrhythmia and to compare the prognostic significance of this parameter with that of other established risk factors. In a series of 71 patients, the risk factors for recurrence of AF during the first year after successful electrical cardioversion were analyzed. A new parameter that was investigated was the frequency of atrial premature beats and the presence of runs of supraventricular tachycardia in the Holter recording started immediately after the cardioversion. Age, left atrial size, left ventricular systolic function, duration of the arrhythmia before cardioversion, underlying cardiac disease, or medication taken were not found to be predictive of recurrence of the arrhythmia. However, the natural logarithm of the number of atrial premature complexes per hour of the Holter recording in the 37 patients in whom AF recurred was higher compared to that of the 34 patients who maintained sinus rhythm (P < 0.0005). The same was true if only the first 6 hours of the recording were analyzed (P < 0.0005). There was a trend for more frequent arrhythmia recurrence if runs of supraventricular tachycardia were present. The finding of > 10 atrial premature complexes per hour in the recording had a relative risk of 2.57 (1.51-4.37), a positive predictive accuracy of 76.5%, and a negative predictive accuracy of 70.3% for subsequent arrhythmia recurrence. We can conclude that frequent (> 10/hour) atrial premature complexes in the Holter recording after electrical cardioversion for AF is a significant risk factor for recurrence of the arrhythmia.

Intravenous magnesium sulfate versus diltiazem in paroxysmal atrial fibrillation.

BACKGROUND: Drugs currently available for the acute treatment of paroxysmal atrial fibrillation have significant limitations. We assessed the safety and effectiveness of intravenous magnesium sulfate versus diltiazem therapy in patients with prolonged episodes of paroxysmal atrial fibrillation. METHODS: In a prospective randomized trial, 46 symptomatic patients presenting with paroxysmal atrial fibrillation were given intravenous magnesium sulfate (n=23) or diltiazem (n=23) therapy. Primary outcome measures were effects on ventricular rate control and proportion of patients restored to sinus rhythm at 6 h after initiation of treatment. RESULTS: There were no differences in baseline characteristics between the two groups. Both forms of treatment were well tolerated, with no adverse clinical events. Both drugs had similar efficacy in reducing the ventricular rate at the first hour of treatment (P<0.05) with a tendency toward a further decrease during infusion times of 2 (P<0.01), 3, 4, 5 and 6 h, respectively (P<0.001). However, at the end of the 6-h treatment period, restoration of sinus rhythm was observed in a significantly higher proportion of patients in the magnesium group compared with the diltiazem group [13 of 23 patients, (57%), versus five of 23 patients, (22%), P=0.03]. CONCLUSIONS: Magnesium sulfate favorably affects rate control and seems to promote the conversion of long lasting episodes of paroxysmal atrial fibrillation to sinus rhythm, representing a safe, reliable and cost-effective alternative treatment strategy to diltiazem.

In-vivo testing of digital cellular telephones in patients with implantable cardioverter-defibrillators.

AIMS: To investigate the susceptibility of implantable cardioverter defibrillators to electromagnetic interference generated by digital cellular telephones, functioning in both international transmission technologies: the Global System for Mobile Communication (GSM) and the Digital Cellular System (DCS 1800). METHODS AND RESULTS: In 36 patients with transvenous implantable cardioverter defibrillators from two manufacturers (Medtronic and Guidant/CPI), cellular telephones with different levels of minimal and maximal power output were tested in the transmitting and receiving mode. Evaluation was performed in activated implantable defibrillators during spontaneous cardiac activity and continuous VVI or DDD pacing to assess possible electromagnetic interference. In two patients, appropriateness of ventricular fibrillation detection and therapy was judged during telephone testing. There was no damage, reprogramming, inappropriate shock therapy or pacing inhibition during the tests. In seven pre-pectoral Medtronic implantable defibrillators, transient electromagnetic interference caused 19 erroneous sensing events, when the operating phone was held in close vicinity to the programmer head. These 'pseudo-oversensing' events, which did not result in logging of arrhythmia episodes in the device counter, were interpreted as an adverse interaction between the telephone and the programming device. CONCLUSION: Digital cellular telephones do not represent a risk to Medtronic and Guidant/CPI recipients of the specific implantable defibrillator models herein tested.

Diagnostic superiority of continuous-loop electrocardiographic recording over other testing in a patient with recurrent syncope and underlying coronary artery disease with severe left ventricular dysfunction.

Dysrhythmic causes of syncope may elude diagnosis in postinfarction patients despite elaborate testing, including electrophysiologic study. For a correct diagnosis, capture of cardiac rhythm during patient's typical symptoms is crucial. This report describes a patient with coronary artery disease and decreased left ventricular ejection fraction who experienced recurrent syncopal episodes without obvious precipitating factors. The 12-lead electrocardiogram showed left bundle-branch block indicating a possible conduction abnormality as the underlying cause of syncope. Twenty-four-h Holter monitoring exhibited no sinus rhythm or conduction disturbances but revealed a nonsustained run of ventricular tachycardia. Findings at electrophysiologic testing led to a presumptive diagnosis of tachyarrhythmic cause of syncope; however, the correct diagnosis was only made with use of a loop monitor which documented a 15-s sinus pause during a syncopal episode.

Ancillary tools in pacemaker and defibrillator lead extraction using a novel lead removal system.

A previous report described our preliminary experience with a highly successful pacing lead removal system (VasoExtor). Extending this experience, we found it necessary to use additional tools to enhance the success of percutaneous lead extraction with this system. In the present series, we used the standard locking stylets (S and K), and recently, one newer type of stylet (Magic) over the last 3 years in 34 patients to extract 48 pacemaker leads in 31 patients and 3 defibrillator (ICD) leads in 3 patients. Lead extraction was carried out in 23 men and 11 women (aged 64 +/- 17 years) because of pacemaker infection (n = 21), pacemaker (n = 8) or ICD (n = 3) lead malfunction, or prior to ICD implant (n = 2). Leads were in place for 3.5 +/- 3.7 years. Infections, involving pocket and lead(s), were due to S. epidermidis (n = 13), S. aureus (n = 6), S. aureus plus E. coli (n = 1), for fungi (n = 1). Of the 48 pacing leads, 31 were ventricular, 15 atrial, and 2 were VDD leads. The ICD leads were two double-coil leads (CPI) and one single-coil lead (Telectronics). Using the S (n = 12), K (n = 8), or Magic (n = 3) stylets, all pacing leads in 23 patients and the ICD leads in 2 patients were successfully removed from a subclavian approach using the locking stylets. However, in nine (26.5%) patients ancillary tools were required. In four patients, lead fragments were captured with use of a noose catheter, a pigtail catheter, and a bioptome from a right femoral approach. In two patients, locking could not be effected and a noose catheter from the right femoral vein was used, aided by a pigtail and an Amplatz catheter and a bioptome to remove three leads. In a patient with an ICD lead, a combined subclavian (stylet S) and right femoral approach (noose catheter) was required. In a patient with a dysfunctional ventricular lead 12 years old, a motor drive unit was used to facilitate the exchange of locking stylets, but extraction failed. In another patient, a fragment of a dysfunctional ventricular lead remained intravascularly despite resorting to a femoral approach. Finally, lead removal was completely (32/34, 94%) or partially (1/34, 3%) successful in 33 (97%) of 34 patients for 50 (98%) of 51 leads without complications. In conclusion, to enhance the success of pacing or ICD lead extraction with use of the VascoExtor locking stylets, an array of ancillary tools were required in more than one fourth of patients.

Right ventricular diastolic function in beta-thalassemia major: echocardiographic and clinical correlates.

BACKGROUND: Cardiac hemochromatosis remains the most frequent cause of death in beta-thalassemia major. Previous studies suggest an important right ventricular (RV) contribution to cardiac morbidity and mortality. Studies with Doppler echocardiography have shown contradictory results regarding left ventricular (LV) filling, whereas the RV filling characteristics have not been studied yet. We prospectively studied the pattern of RV filling and investigated echocardiographic and clinical correlates during baseline and follow-up examinations in patients with beta-thalassemia major. METHODS AND RESULTS: The study included 79 patients, aged 24.2 +/- 8.0 years, with homozygous beta-thalassemia major without symptoms of heart failure with normal LV function and 51 healthy control subjects, matched for age, sex, and body surface area. Doppler echocardiographic indexes of systolic and diastolic ventricular function were assessed. Hemodynamic measurements were obtained in 8 patients by right heart catheterization. An abnormal RV relaxation pattern was evident in the patient group. The LV filling characteristics indicated increased preload without abnormal alteration, whereas catheterization findings were consistent with a high cardiac output state. Short tricuspid deceleration time (DT) had the best predictive value for subsequent cardiac events. Repeat echocardiographic study in 35 asymptomatic patients at 19 +/- 7 months demonstrated deterioration of LV systolic function, chamber enlargement, and shortening of DT of tricuspid and mitral inflow. CONCLUSIONS: In patients with homozygous beta-thalassemia major without cardiac disease, the pattern of RV filling is abnormally altered, indicating impaired relaxation. In contrast, the LV filling is compatible with increased preload, as in chronic anemia. Short DT of early tricuspid inflow carries important prognostic value. LV remodeling occurs over time along with transition toward a restrictive ventricular filling pattern.

Initial experience with a newer generation coronary stent.

BACKGROUND: Recently, several newer generation stents have become available promising to improve upon the results of coronary angioplasty (PTCA) with its attendant acute and chronic complications. The aim of this study was to prospectively review the results of a preliminary experience with the newer generation R stent in a series of 56 patients. METHODS: This study included 47 men and 9 women, aged 57 +/- 10 years, who presented with stable angina and/or positive exercise testing (n = 12), unstable angina (n = 42), or acute myocardial infarction (n = 2). A consistent approach by a single operator for implantation of the R stent (Orbus Inc., The Netherlands) included stent oversizing (by 0.5 mm) and high pressure (> 12--16 bar) deployment. Dilated vessels comprised the left anterior descending (n = 37) including the diagonal branch in 2 patients, the right coronary artery (n = 17), the left circumflex (n = 13), or a saphenous vein graft (n = 1). The mean left ventricular ejection fraction was 52 +/- 8% and the initial coronary artery stenosis was 85 +/- 8%. Stents were implanted for dissection and/or suboptimal PTCA result or electively. RESULTS: The procedure was successful in all 56 patients (100%). The residual stenosis was < 0--10%. Direct stenting without balloon predilation was performed in 21 patients. Single stents were used in 36 patients and > or = 2 stents in 20 patients. Abciximab (n = 22), eptifibatide (n = 8) or tirofiban (n = 1) was administered in 31 patients (55%). A stent-related complication was noted in one patient (stent misplacement). All patients were discharged alive without infarct or need for surgery. There were no events of subacute stent thrombosis; all patients received combined therapy with aspirin and clopidogrel, the latter for 1 month. In one patient who had received abciximab, severe thrombocytopenia (0 platelet count) was detected at 3 days after discharge but it was fully reversible with no sequelae. Over 5.2 +/- 2.8 (range, 1--11) months, there was one sudden death and two clinical restenoses; no other late complication occurred. CONCLUSION: Initial experience with 73 R stents in 56 patients and a consistent approach by a single operator of stent oversizing and high-pressure deployment resulted in high procedural success (100%), lack of stent thrombosis (0%), and a low stent-related complication rate (1.8%), while the design and profile of the R stent allowed for direct stenting in 37.5% of patients. One should be vigilant for the sporadic occurrence of severe thrombocytopenia with use of IIb/IIIa inhibitors.

Reduced incidence of clinical restenosis with newer generation stents, stent oversizing, and high-pressure deployment: single-operator experience.

BACKGROUND: Over the last 4 years, several newer generation stents have become available, promising to change the scenery of coronary angioplasty (PTCA) with its attendant restenosis rate. HYPOTHESIS: The aim of this study was to review prospectively the results of a single operator adopting a uniform approach with approximately 0.5 mm stent oversizing and high-pressure (> or = 12-16 bar) deployment and compare them with conventional PTCA in a series of 244 consecutive patients. METHODS: The study included 203 men and 41 women, aged 59 +/- 11 years, who presented with stable angina and/or positive exercise testing (n = 75), unstable angina (n = 161), or acute myocardial infarction (n = 8). Dilated vessels included the left anterior descending artery (n = 139), the right coronary artery (n = 86), the left circumflex artery (n = 47), the ramus branch (n = 4), or venous grafts (n = 2). Stents were implanted for dissection, suboptimal PTCA result, and electively. Two groups were compared: 83 patients who underwent balloon PTCA alone and 161 patients who also received stent(s). RESULTS: The two groups had similar demographics, age (58 +/- 10 vs. 59 +/- 11 years), initial vessel stenosis (92 +/- 7 vs. 93 +/- 6%), and left ventricular ejection fraction (51 +/- 9 vs. 51 +/- 8%). Procedural success was also similar (97.6 vs. 99.4%), but as expected the residual stenosis was much lower in the stent group (< or = 0 vs. 17%). The following stents were employed: J & J (n = 1), NIR (n = 117), ACS (n = 59), AVE (n = 9), Inflow GoldFlex (n = 9), Crossflex (n = 5), Wictor (n = 1), Jostent (n = 16), R stent (n = 9), Seaquence (n = 2) and Wallstent (n = 1). Single stents were used in 118 patients, two stents in 31 patients, three in 6 patients, and four in 6 patients. There was one in-hospital death at 3 days unrelated to the procedure. There were no events of subacute stent thrombosis; all patients in the stent group received combined therapy with aspirin and ticlopidine, the latter for 1 month. During 18 +/- 14 months, the clinical restenosis rate was significantly lower in the stent group (6.9%) than in the PTCA group (28.4%) (p = 0.001). CONCLUSION: In a series of 244 consecutive patients, newer generation stents and a consistent approach of stent oversizing and high-pressure stent deployment by a single operator resulted in high procedural success (99%), lack of stent thrombosis (0%), and a very low clinical restenosis rate (7%).

Usefulness of reperfusion ventricular arrhythmias in non-invasive prediction of early reperfusion and sustained coronary artery patency in acute myocardial infarction.

BACKGROUND: Established tenets of occurrence of reperfusion ventricular arrhythmias in acute myocardial infarction (AMI) do not provide insight into the timing of achieving reperfusion or whether coronary artery patency is sustained. We assessed the significance of ventricular arrhythmias in the non-invasive prediction of timely reperfusion and sustained restoration of coronary patency after thrombolysis in patients with AMI. METHODS: 24-hour Holter monitors were placed in 163 patients with an AMI before administration of thrombolytic therapy. Patients were classified into 3 groups of early (within 2 hours) or late reperfusion, or no-reperfusion, according with clinical and continuous ST-segment electrocardiographic criteria. Ventricular fibrillation, ventricular tachycardia (VT) and accelerated idioventricular rhythm (AIVR) were also categorized as having occurred early (within the first 2 hours) or late (after the first 2-hour period). Angiographic confirmation of coronary patency was determined 2 to 6 days after AMI. RESULTS: Early reperfusion was predicted by early sustained AIVR in 86% of patients and early non-sustained AIVR in 62.5% of patients, with sensitivity 38% and 77%, and specificity 96% and 69%, respectively; p<0.0001. Late non-sustained AIVR was commonly seen in early and late reperfused patients (92-97%) as well as in non-reperfused patients (74%). Sustained coronary patency was predicted by early sustained AIVR in 93% of patients, as well as by early non-sustained AIVR in 86% of patients and late non-sustained AIVR in 79% of patients, with sensitivity 22%, 55% and 94%, and specificity 95%, 71% and 18%, respectively; p<0.05. CONCLUSION: Only the occurrence of sustained AIVR, and probably early non-sustained AIVR convey useful information about both early reperfusion and sustained coronary artery patency. The absence of AIVR does not preclude successful thrombolysis.

VDD pacing from the middle cardiac vein via a persistent left superior vena cava.

We report a combination of unusual features demonstrating a permanent pacemaker implantation of a single-pass VDD lead by way of an anomalous persistent left superior vena cava in the middle cardiac vein. The ventricular stimulation resembled a right bundle branch block QRS morphology and was successfully synchronized by spontaneous atrial activity. This case illustrates an alternative approach of effective VDD pacing and sensing in patients with such a venous anomaly when other standard implantation sites fail.

Significance of R-on-T phenomenon in early ventricular tachyarrhythmia susceptibility after acute myocardial infarction in the thrombolytic era.

We investigated the clinical significance and mechanism of the R-on-T phenomenon in the current thrombolytic era as potential precipitant of R-on-T-induced early ventricular tachyarrhythmias in patients with a thrombolysed acute myocardial infarction. We also examined the role of QT dispersion on ventricular vulnerability and its association with R-on-T-initiated ventricular tachyarrhythmias. A total of 93 patients underwent 24-hour Holter monitoring starting at hospital admission before thrombolysis. Patients were classified into 2 groups: those with (n = 76) and those without (n = 17) reperfusion according to electrocardiographic criteria. All R-on-T ventricular premature complexes (VPCs) and R-on-T-initiated arrhythmic events (ventricular tachycardia [VT], ventricular fibrillation) were counted to estimate arrhythmia density and severity in 2 time periods during and after completion of thrombolysis. Measurements of QT and QTc intervals and dispersion parameters were obtained on the 12-lead electrocardiogram before thrombolysis and at 24 hours in patients with and without R-on-T VTs. Overall, R-on-T VPCs were rarely observed (1.8% of total VPCs over 24 hours), occurring more frequently during than after thrombolysis (at a rate of 8 vs 0.6 VPCs/hour, p = NS) and at a higher rate during thrombolysis in nonreperfused than in perfused patients (15 vs 8/hour, p = NS). Three VF episodes were observed in 1 reperfused patient, and all were R-on-T initiated. Episodes of nonsustained R-on-T VTs (3.3% of total VTs over 24 hours) appeared more frequent during than after thrombolysis (at a rate of 0.8 vs 0.05 VPCs/ hour, p = NS), and compared with non-R-on-T VTs they were significantly faster (374 +/- 56 ms vs 411 +/- 69 ms; p < 0.05), with a trend toward longer duration. Our findings indicate that R-on-T VPCs and R-on-T VTs are early rare features in acute myocardial infarction, and do not serve as triggers of severe ventricular tachyarrhythmia. The study of ventricular repolarization did not elicit an identifiable risk factor of R-on-T VT susceptibility.