Stelios Paraskevaidis

Spontaneous Dissection of Right Coronary Artery Manifested with Acute Myocardial Infarction

Spontaneous coronary artery dissection is a rare cause of acute ischemic coronary events and sudden cardiac death. It usually occurs in young women without traditional risk factors for coronary artery disease during pregnancy or postpartum period. However, it has also been reported in patients with atherosclerotic coronary disease. We present a case of spontaneous right coronary artery dissection in a 48-year male with recent myocardial infarction and previous percutaneous coronary intervention.

QRS analysis using wavelet transformation for the prediction of response to cardiac resynchronization therapy: a prospective pilot study.

BACKGROUND Wider QRS and left bundle branch block morphology are related to response to cardiac resynchronization therapy (CRT). A novel time-frequency analysis of the QRS complex may provide additional information in predicting response to CRT. METHODS Signal-averaged electrocardiograms were prospectively recorded, before CRT, in orthogonal leads and QRS decomposition in three frequency bands was performed using the Morlet wavelet transformation. RESULTS Thirty eight patients (age 65±10years, 31 males) were studied. CRT responders (n=28) had wider baseline QRS compared to non-responders and lower QRS energies in all frequency bands. The combination of QRS duration and mean energy in the high frequency band had the best predicting ability (AUC 0.833, 95%CI 0.705-0.962, p=0.002) followed by the maximum energy in the high frequency band (AUC 0.811, 95%CI 0.663-0.960, p=0.004). CONCLUSIONS Wavelet transformation of the QRS complex is useful in predicting response to CRT.

Intermittent P wave sensing in a patient with DDD pacemaker.

We present the case of a patient with a DDD pacemaker and intermittent P wave sensing due to T wave oversensing by the ventricular lead. The T wave sensing caused initiation of an extended atrial refractory period and the P waves, falling within this period, were not sensed. The problem was solved by decreasing the ventricular sensitivity.

Practice patterns of cardiologists, general practitioners, and internists for managing supraventricular tachycardias in Greece

Objectives Supraventricular tachycardias (SVT) often lead to emergency room and primary care visits. Not only cardiologists, but also general practitioners (GPs) and internists are involved to an increasing extent in the acute and long-term management of SVT. We aimed to explore the differences between practice patterns of cardiologists and noncardiologists with regard to SVT management in Greece. Methods A cross-sectional questionnaire survey was conducted among 250 cardiologists and 250 GPs/internists from various areas across Greece. Results A response rate of 61.8% was obtained. Vagal maneuvers were the initial therapeutic approach for SVT termination; however, 22% of noncardiologists would rather start with an antiarrhythmic drug. Adenosine was the most popular drug for SVT termination, but the GPs/internists would use it less often than the cardiologists (67 vs. 86%, P<0.001). The GPs/internists would keep the patient for at least 24 h or more after SVT termination, while 48% of the cardiologists would discharge the patient within the first 3 h. Noncardiologists would more often suggest a 24-h Holter recording than the cardiologists (73 vs. 55%, P<0.005). With regard to the long-term management of SVT, the GPs/internists would prescribe antiarrhythmic drugs earlier than the cardiologists, and seem to be less familiar with the indications for the electrophysiological testing and ablation. Conclusion Significant differences in practice patterns exist in Greece with regard to SVT management between cardiologists and noncardiologists. The GPs/internists seem to rely more on antiarrhythmic drugs and tend to underestimate the role of ablation therapy for the long-term management of SVT.

Idiopathic left ventricular aneurysm causing ventricular tachycardia with 1:1 ventriculoatrial conduction and intermittent wenckebach block.

Left ventricular aneurysms (LVAs) can be congenital or acquired. They develop most frequently after myocardial infarction. Other causes include hypertrophic cardiomyopathy, arrythmogenic right ventricular cardiomyopathy, myocarditis, chest trauma, sarcoidosis or Chagas disease [1, 2]. LVAs without identifiable cause are considered as idiopathic. Most of LVAs are asymptomatic and are occasionally identified during routine diagnostic procedures. However, in rare cases LVAs may be associated with life-threatening ventricular tachyarrhythmias (mostly ventricular tachycardia, VT) and sudden cardiac death, even as a first manifestation [3]. In most of the cases VT has right bundle branch block morphology consistent with left ventricular origin. Idiopathic LVAs are anatomically distinguished from congenital diverticula, which are characterized by a narrow communication with the ventricle [2, 4]. In this report we describe an interesting and rare case of idiopathic LVA associated with sustained monomorphic VT, ventriculoatrial conduction and intermittent Wenckebach block. Management strategies are discussed and our treatment approach is presented. Case Report A 72-year old woman was admitted to our hospital with palpitations, dizziness and fatigue from a few hours ago. The patient had a history of heart failure (NYHA II) from three years ago and also an episode of paroxysmal atrial flutter two years ago. She was free of angina and had no cardiovascular disease risk factors. The family history was unremarkable with respect to cardiac arrest, unexplained syncope, ventricular tachyarrhythmias, or cardiomyopathy. At the time of presentation to the emergency department the patient was receiving carvedilol, valsartan, and furosemide. The baseline 12-lead ECG revealed a sustained monomorphic VT with RBBB morphology and left axis deviation (Fig. ​1A1A). Since tachycardia was poorly tolerated with systolic blood pressure of 80 mmHg an electrical cardioversion was applied and the rhythm was restored to sinus (Fig. ​1B1B). The ECG, physical examination and laboratory tests after the cardioversion were unremarkable. Fig. (1A) ECG on admission showing the ventriculat tachycardia (VT) with RBBB morphology, (B). Restoration of VT to sinus rhythm with electrical cardioversion, (C). Induced VT with LBBB morphology during the electrophysiology study, (D). Electrogram during the ... The chest X-ray revealed an increased cardiothoracic index. The transthoracic echocardiogram showed dilated left ventricle with a lateral wall aneurysm, left ventricular ejection fraction of 40% and mild mitral regurgitation (Fig. ​2A2A). The coronary angiography revealed normal coronary arteries, whereas the left ventriculography further confirmed the lateral wall aneurysm (Fig. ​2B2B). Magnetic resonance imaging further confirmed the presence of the LVA (Fig. ​2C2C). Fig. (2A) Echocardiogram showing the left ventricular aneurysm (arrows), (B). Left ventriculography further depicting the lateral wall aneurysm (arrows), (C). Magnetic resonance imaging further confirmed the presence of an aneurysm with wall thinning (arrows). The patient was started on amiodarone per os and after two weeks an electrophysiology study was performed. The programmed ventricular stimulation in the right ventricular apex with 500/230-240 msec basic drive cycle and two extrastimuli reproducibly induced sustained monomorphic VT of 160 bpm associated with hemodynamic instability. That tachycardia, however, had different characteristics from the one at the emergency department as it was associated with left branch bundle block (LBBB) morphology and normal cardiac axis and was terminated by overdrive pacing (Fig. ​1C1C). The LBBB morphology was consistent with septal origin of the VT. Of note, during the inducible VT a 1:1 ventriculoatrial conduction with intermittent Wenckebach block was recorded (Fig. ​1D1D). A cardioverter defibrillator (ICD) was implanted for the secondary prevention of VT and the patient was discharged 2 days after ICD implantation on treatment with carvedilol, amiodarone and angiotensin converting enzyme inhibitor. During a follow-up period of six months no ventricular arrhythmias occurred.

Atrial fibrillation in hypertrophic cardiomyopathy: A turning point towards increased morbidity and mortality☆

BACKGROUND Atrial fibrillation (AF) is the most common arrhythmic event in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to identify the clinical impact and prognostic significance of AF on a large cohort of patients with HCM. METHODS Echocardiographic and clinical correlates, risk factors for AF and thromboembolic stroke and the prognostic significance of AF were evaluated in 509 patients with an established diagnosis of HCM. RESULTS A total of 119 patients (23.4%) were diagnosed with AF during the index evaluation visit. AF patients had a higher prevalence of stroke and presented with worse functional impairment. Left atrial diameter (LA size) was a common independent predictor of the arrhythmia (OR: 2.2, 95% CI 1.6-3.3) and thromboembolic stroke (OR: 1.6, 95% CI 1.01-2.40). AF was an important risk factor for overall mortality (HR=3.4, 95% CI: 1.7-6.5), HCM-related mortality (HR=3.9, 95% CI: 1.8-8.2) and heart failure-related mortality (HR=6.0, 95% CI: 2.0-17.9), even after adjusting for statistically significant clinical and demographic risk factors. However, AF did not affect the risk for sudden death. CONCLUSIONS LA size is an independent predictor of both AF and thromboembolic stroke. Moreover, patients with AF, regardless of type, have significantly higher mortality rates than patients without AF.

The role of catheter ablation in the management of patients with implantable cardioverter defibrillators presenting with electrical storm

OBJECTIVE Electrical storm (ES) is not uncommon among patients with an implantable cardioverter defibrillator (ICD) in situ. Catheter ablation (CA) may suppress the arrhythmia in the acute setting and prevent ES recurrence. METHODS Nineteen consecutive patients with an ICD in situ presenting with ES underwent electrophysiologic studies followed by CA. CA outcome was classified as a complete success if both clinical and non-clinical tachycardia were successfully ablated, partial success if ≥1 non-clinical tachycardia episodes were still inducible post-CA, and failure if clinical tachycardia could not be abolished. Patients were followed for a median period (IQR) of 5.6 (1.8-13.7) months. The primary endpoint was event-free survival from ES recurrence. The secondary endpoint was event-free survival from a composite of ES and/or sustained ventricular tachycardia (VT) recurrence. RESULTS Clinical arrhythmia was successfully ablated in 14 out of 19 (73.7%) cases after a single CA procedure. A completely successful CA outcome was associated with significantly increased ES-free survival compared with a partially successful or failed procedure (Log rank P=0.039). Nevertheless, patients with acute suppression of all tachycardia episodes (n=11), relative to those with a partially successful or a failed CA procedure (n=8), did not differ in incidence of the composite endpoint of sustained VT or ES (Log rank P=0.278). CONCLUSION A single CA procedure can acutely suppress clinical arrhythmia in three-quarters of cases. A completely successful CA outcome can prolong ES-free survival; however, sporadic ICD therapies cannot be abrogated.

Cardiac arrest caused by torsades de pointes tachycardia after successful atrial flutter radiofrequency catheter ablation.

A 66-year-old woman underwent successful radiofrequency catheter ablation for long-lasting, drug refractory fast atrial flutter. Two days later she had a cardiac arrest due to torsades de pointes (TdP) tachycardia attributed to relative sinus bradycardia and QT interval prolongation. After successful resuscitation further episodes of TdP occurred, which were treated with temporary pacing. Because of concomitant systolic dysfunction due to ischemic and valvular heart disease she was finally treated with an implantable defibrillator. In conclusion we strongly advise prolonged monitoring for 2 or more days for patients with structural heart disease following successful catheter ablation for long lasting tachyarrhythmias.

Ibutilide for the Cardioversion of Paroxysmal Atrial Fibrillation during Radiofrequency Ablation of Supraventricular Tachycardias.

Direct current electrical cardioversion (DC-ECV) is the preferred treatment for the termination of paroxysmal atrial fibrillation (AF) that occurs during radiofrequency ablation (RFA) of supraventricular tachycardias (SVT). Intravenous Ibutilide may be an alternative option in this setting. Thirty-four out of 386 patients who underwent SVT-RFA presented paroxysmal AF during the procedure and were randomized into receiving ibutilide or DC-ECV. Ibutilide infusion successfully cardioverted 16 out of 17 patients (94%) within 17.37 ± 7.87  min. DC-ECV was successful in all patients (100%) within 17.29 ± 3.04  min. Efficacy and total time to cardioversion did not differ between the study groups. No adverse events were observed. RFA was successfully performed in 16 patients (94%) in the ibutilide arm and in all patients (100%) in the DC-ECV arm, p = NS. In conclusion, ibutilide is a safe and effective alternative treatment for restoring sinus rhythm in cases of paroxysmal AF complicating SVT-RFA.

Fragmented QRS and Ventricular Dyssynchrony in a Patient Treated with Cardiac Resynchronization Therapy

Cardiac resynchronization is an established treatment modality in patients with heart failure NYHA class III-IV on optimal medical treatment, QRS duration of at least 120-130 ms and ejection fraction <35%. Nevertheless, a propor- tion of patients, up to 20-30%, are considered non-responders as they are not improved by cardiac resynchronization ther- apy (CRT). This report describes a 63-year-old patient with ischemic cardiomyopathy, severe mitral regurgitation, and fragmented QRS complex in several leads. The patient had LV dyssynchrony identified by echocardiographic tissue Dop- pler imaging. A biventricular pacemaker was implanted successfully, and resulted in improvement in LV dyssynchrony, LV dimensions, mitral regurgitation and symptoms. Fragmented QRS complex as a marker of ventricular dyssynchrony may play a role in identifying patients who may benefit from cardiac resynchronization therapy.