The impact of intravascular ultrasound guidance during drug eluting stent implantation on angiographic outcomes.

OBJECTIVE: Major limitation for the use of stent in the treatment of coronary artery disease is development of stent restenosis. The impact of intravascular ultrasound (IVUS) guidance during drug eluting stent (DES) implantation is presently not yet well established. PATIENTS AND METHODS: For the present study, we included 30 patients who received DES with IVUS-guided stenting (Group A) and 30 patients receiving the DES without IVUS-guided stenting (Group B). The patients were evaluated for their ninth month control angiographies and were followed during two years for the development of relevant clinical events after the DES implantations. The angiographic and clinical results were compared between the groups. RESULTS: After the percutaneous intervention, the minimal luminal diameter and net acute gain were significantly increased in Group A in respect to Group B (3.3 ± 0.34 vs. 2.8 ± 0.33, p < 0.01). Moreover, the rate for performing post-dilatation following stent implantation was higher in Group A than in Group B (p = 0.01). By contrast, stent restenosis rates were similar between the groups (p > 0.3). CONCLUSIONS: The present results indicate that the use of IVUS for the implantation of DES can increase the success rate of the intervention. The IVUS guidance during DES implantation can be complementary percutaneous intervention, in particularly by detecting the situations that need for post-dilatation.

Zwolle risk score predicts contrast-induced acute kidney injury in STEMI patients undergoing PCI.

OBJECTIVE: Contrast-induced acute kidney injury (CI-AKI) is a common complication in patients with acute ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). The Mehran risk score was defined originally in elective PCI and may be predictive of CI-AKI. The aim of the present study was to investigate whether the Zwolle score predicts CI-AKI in patients with acute STEMI undergoing primary PCI. PATIENTS AND METHODS: We analyzed the data of 314 consecutive patients (mean age 56.3 ± 11.4 years) with acute STEMI undergoing primary PCI. The study population was divided into two groups according to CI-AKI development. The Mehran score, Zwolle score, baseline characteristics, and in-hospital outcomes were recorded. RESULTS: Patients with CI-AKI had higher Mehran and Zwolle scores. In a receiver operating characteristic (ROC) curve analysis, high area under the curve (AUC) values were determined for Zwolle and Mehran scores (0.85 and 0.79, respectively) for CI-AKI development. A Zwolle score greater than 2 predicted CI-AKI with a sensitivity of 76.3 % and a specificity of 75.4 %. A Mehran score greater than 5 predicted CI-AKI with a sensitivity of 71.1 % and a specificity of 73.6 %. CONCLUSION: Zwolle score predicts CI-AKI slightly better than the Mehran score in patients with STEMI undergoing primary PCI. This simple score can be used at the catheterization laboratory for risk stratification for the development of CI-AKI.

Relationship between hypoplastic right coronary artery and coronary artery anomalies.

OBJECTIVES: The frequency of hypoplastic right coronary artery (HRCA) and its contribution to coronary artery anomalies (CAAs) has not been thoroughly studied. Here we aimed to investigate whether a casual relationship exists between the presence of HRCA and CAAs. MATERIALS AND METHODS: We retrospectively reviewed coronary angiography records of 7500 patients. The images were carefully assessed for coronary artery (CA) anatomy and CAAs. Overall, we compared CAAs at the presence and absence of HRCA and evaluated potential association between HRCA and CAAs. Besides, we grouped HRCA patients according to the presence of CA disease (CAD) into two groups and compared their CAAs. RESULTS: While the percentage of HRCA was 6.2%, it was 3.34% for CAAs. The percentage of CA with anomalous origin (CAAO) at the presence of HRCA was significantly higher than the presence of normal right coronary artery (NRCA) (p < 0.01). Similarly, the percentage of absent left main coronary artery (ALMCA) was also considerable increased in HRCA patients with respect to the patients with NRCA (p < 0.01). The percentage of CAAO was notably higher in the CAD (-) than CAD (+) patients with HRCA (p < 0.01). Likewise, the prevalence of ALMCA was also noticeably higher in the CAD (-) than CAD (+) patients with HRCA (p < 0.01). CONCLUSIONS: HRCA is a clinically significant and frequently encountered congenital variation. The present observations indicate that the presence of HRCA is closely associated with a high prevalence of CAAO, particularly with increased rate of ALMCA.

Percutaneous treatment of totally occluded the coarctation of the aorta with angioplasty and stenting.

The coarctation of the aorta (CoA) is one of the most frequently encountered congenital heart diseases and in most of cases it is characterized with a discrete narrowing localized on the thoracic aorta just distal to the left subclavian artery. The incidence of totally occluded CoA is very rare. The treatment options for CoA include surgical approaches, transcatheter balloon angioplasty, or stent placement. Although stenting has been the preferred method for the treatment of CoA, few studies exist in the literature regarding the use of stenting approach in the treatment of total occluded CoA. Therefore, we aimed to present a CoA patient treated using material and techniques used in the standard treatment of chronic total occlusion of coronary arteries.

Thrombectomy and distal protection devices.

Visible distal embolization is a relatively rare complication during percutaneous coronary interventions but it may occur in 15-20% of angioplasties in saphenous vein grafts (SVG) and in thrombus containing lesions of native coronary arteries, especially in the setting of acute myocardial infarction (AMI). Mechanical thrombectomy devices and distal protection devices have been introduced to reduce the incidence of distal embolisation. Angiojet thrombectomy has shown positive outcomes in thrombus containing lesions when compared with intracoronary thrombolysis but a randomised trial failed to show benefit in the context of AMI. The X-Sizer, Excimer LASER and various simple aspiration thrombectomy catheters show promise in treatment of AMI with improvement shown in surrogate end-points such as resolution of ST-elevation but there have been no randomised trials large enough to demonstrate changes in hard clinical end-points. Distal protection devices have come to be routinely used during SVG treatment and, after the results of the SAFER and FIRE trials; they became a treatment recommendation in the recently issued European Society of Cardiology (ESC) guidelines. For AMI, these devices showed great promise in early single-centre studies which have been offset by the lack of clinical benefit in the multi-centre EMERALD trial. Proximal occlusion devices may further decrease the incidence of distal embolisation, especially in the treatment of totally occluded SVGs or native arteries, by reversing the blood flow and offering protection at a very early stage of the procedure before wire passage. Despite continuous technical improvement and a growing number of miniaturised thrombectomy devices and filters, because of the paucity of controlled large studies, it remains unclear whether these devices will remain limited to niche' applications or will become a regular companion to balloons and stents in mainstream angioplasty procedures.

Electrical cardioversion of atrial fibrillation in a case of dextrocardia.

Although atrial fibrillation is one of the most frequent and widespread cardiac arrhythmias, there is not sufficient data on frequency and electrical cardioversion of this arrhythmia in cases of dextrocardia. The present case report describes a 66-year-old woman with atrial fibrillation and dextrocardia who was admitted to hospital with a complaint of palpitations; no cause of the atrial fibrillation was found. Electrical cardioversion was performed for termination of the arrhythmia. By placing the anterior paddle in the right parasternal area and the lateral paddle in the area where the apex of the left ventricle palpated at the right side of the chest, cardioversion was performed and sinus rhythm was achieved.

Detection of myocardial injury after internal cardioversion for atrial fibrillation.

BACKGROUND: Cardiac troponin levels do not rise to marked levels after external cardioversion of atrial fibrillation. Subsequent test discharges during implantation of cardioverter defibrillators may cause an elevation of cardiac troponin levels, but are still controversial. OBJECTIVE: To determine whether the biomarkers of cardiac injury increase after internal cardioversion (IC) of atrial fibrillation. METHODS: Forty-four patients with chronic atrial fibrillation were studied (mean age 59 +/-7 years). Electrode catheters were inserted through the femoral vein. One of these was positioned in the lower right atrium. A second defibrillation electrode was placed in the coronary sinus and an additional catheter was positioned in the right ventricular apex in order to obtain satisfactory R wave synchronization and to provide postshock ventricular pacing. The shocks were delivered by external defibrillator. Starting with a test shock of 1 J intensity, the energy was increased in steps (to maximum 15 J) until cardioversion was achieved. At least 1 min was permitted to elapse between unsuccessful defibrillation attempts before the next shock was applied. Blood samples for serum levels of cardiac troponin T, cardiac troponin I, creatine kinase MB and myoglobin were drawn before and 2 h, 4 h, 8 h and 24 h after IC. Each level of biomarker was compared with baseline. RESULTS: In 40 of 44 patients, IC was successful at a mean cardioversion threshold of 7.6+/-3.3 J. Although the serum levels of these biomarkers tended to rise, marked elevation was not detected in any of samples (P>0.05 for each). There was no correlation between the levels of biomarkers and the number and energy of shocks applied. No severe complications were observed. CONCLUSIONS: Following uncomplicated IC of atrial fibrillation, cardiac biomarkers do not rise to marked levels, which indicates that significant myocardial injury does not occur by shocks in the usual dosage.

Clinical importance of the initiation pattern of monomorphic ventricular tachycardia.

We investigated the clinical and electrophysiological features of monomorphic ventricular tachycardia (MVT) with different initiation patterns in patients with implantable cardioverter defibrillator to assess whether there is a relationship between the initiation patterns of sustained MVT and clinical characteristics, and the efficacy of antiarrhythmic and electrical therapy. Fifty-five stored IECGs in twenty-two patients with MVT were evaluated. All MVT episodes were classified as initiating with ventricular premature beats (non-sudden onset MVT) or without ventricular ectopy preceding tachycardia (sudden onset MVT). Non-sudden onset MVT was characterized by shorter tachycardia cycle length (CL) and required higher shock energy for termination. Sudden onset MVT was precipitated by shortening of the sinus CL before tachycardia and was more common with relatively better preserved systolic function.

Long-short sequence may predict immediate recurrence of atrial fibrillation after external cardioversion.

AIM: We thought, that analysis of surface electrocardiograms recorded immediately after electrical external cardioversion (EC) might enlighten the mechanisms responsible for immediate recurrence of atrial fibrillation (AF) and especially to test whether atrial ectopic beats (PAC) with long-short (LS) sequence are related to the recurrence of arrhythmia after cardioversion in patients with chronic AF. METHODS AND RESULTS: One hundred and thirty-seven patients (mean age 57+/-7 years) undergoing EC for chronic AF entered the study. Evaluation of the patients included clinical history, physical examination, ECG, routine laboratory tests, and transthoracic echocardiography. The cardioversion was performed with monophasic waveform shock and immediately after successful EC, 1 min of recording of the ECG lead II was analysed. One hundred and twenty patients (87%) of 137 patients enrolled in the study had had successful EC and 33 (27%) of them experienced immediate recurrence of AF within 1 min (Group I) and 87 patients had no arrhythmia recurrence (Group II). In group I in 24 patients (73%) recurrence of AF was initiated by PAC with LS sequence. In only 12 of 87 (13%) patients who did not experience immediate recurrence of AF (Group II) PACs were recorded. CONCLUSIONS: Atrial ectopic beats (PACs) with LS sequence, being responsible for AF relapse in about 70% of patients, might predict early re-initiation of arrhythmia after EC. Electrocardiograms, recorded immediately after EC, are a potentially feasible approach in establishing the patterns of AF relapse that may be useful in the management of AF recurrence.

Implantable event loop recorder prevents misdiagnosis of underlying arrhythmia in patients with unexplained palpitations--a case report.

The implantable event loop recorder is informative in the establishment of underlying arrhythmia and may aid in treatment of patients with infrequent unexplained palpitations.

Parahisian radiofrequency catheter ablation in dogs: comparison of the above-valve and below-valve approaches.

In patients with an accessory pathway close to the His bundle, radiofrequency catheter ablation (RFCA) requires additional care to avoid damage to the normal conduction system. To assess differences between approaches from above or below the tricuspid valve (TV), we performed RFCA in 20 dogs (from above, group A, n=10; from below, group B, n=10). RF energy with temperature control at 60 degrees 60 seconds was administered at the site where a small His potential was recorded from the ablation catheter guided by fluoroscopy and transesophageal echocardiography (TEE) (in the latter six dogs). Before and after RFCA, electrophysiological testing was performed and histological findings were compared. An ablated lesion was created in 7 of 10 (2 of 2 guided by TEE) dogs in group A and 5 of 10 (3 of 4 TEE) dogs in group B. In group A, an ablated lesion involved the atrium and ventricle in the anterior site of His bundle, but the lesion was only in the ventricle in group B. An atrioventricular block (AVB) and severe damage to the penetrating bundle was observed in one dog of group A. A large hematoma on the TV was made in 2 dogs and the complete right bundle branch block (CRBBB) occurred in 3 dogs of group B. The approach from below the TV was safer than that from above the TV in parahisian RFCA, because it did not create an AVB, although it has a high incidence of CRBBB and associated technical difficulties.

Relation of plasma lipoprotein(a) with myocardial viability and left ventricular performance in survivors of myocardial infarction.

Previous studies have reported that high serum lipoprotein(a) levels may be responsible for total occlusion of the infarct-related artery via inhibition of intrinsic fibrinolysis during acute myocardial infarction. We evaluated whether this would result in a greater extent of myocardial necrosis and impaired left ventricular function in patients with high lipoprotein(a) levels. Sixty-eight patients with prior myocardial infarction, who were not receiving thrombolytic therapy underwent coronary angiography and stress-redistribution-reinjection Tl-201 scintigraphy. Antegrade TIMI flow in the infarct-related artery was lower (1.54 +/- 1.14 vs 2.15 +/- 1.05; p = 0.03) and the collateral index was higher (1.3 +/- 1.0 vs 0.8 +/- 0.9; p = 0.07) in patients with high lipoprotein(a) levels (> 30 mg/dl) compared to those with low lipoprotein(a) levels (< or = 30 mg/dl). Regional wall motion score index was lower (0.8 +/- 0.8 vs 1.4 +/- 0.5; p = 0.008) and global ejection fraction was higher (46 +/- 10% vs 40 +/- 11%; p = 0.03) in patients with low lipoprotein(a) levels. On SPECT images, the number of non-viable defects was higher in patients with high lipoprotein(a) levels (4.0 +/- 2.5 vs 1.9 +/- 1.3; p = 0.0002), whereas the number of viable defects was higher in those with low lipoprotein(a) levels (2.5 +/- 1.8 vs 1.5 +/- 1.3; p = 0.02). We conclude that high lipoprotein(a) levels may prolong the occlusion of infarct-related artery during acute myocardial infarction and lead to a greater extent of myocardial necrosis and impaired left ventricular function.