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Konstantinos P Letsas

Publications and source records attributed to Konstantinos P Letsas.

At least 19 recordsLinked to original sources
PubMed2026

Clinical Profile and Mode of Initiation of Spontaneous Ventricular Tachyarrhythmias in Patients With Brugada Syndrome (START-BrS).

BACKGROUND: Data on the spontaneous onset of ventricular tachyarrhythmias (VTAs) in Brugada syndrome (BrS), including polymorphic ventricular tachycardia (PVT) and monomorphic ventricular tachycardia (MVT), remain limited. OBJECTIVES: The goal of this study was to compare the clinical profile and mode of initiation of PVT and MVT in BrS. METHODS: This retrospective multicenter registry included 154 patients with BrS from 29 centers with documented VTA initiation captured by implantable cardioverter-defibrillator (94.9%) or electrocardiogram (5.1%). A total of 234 VTAs were analyzed, and initiation patterns were classified by using predefined electrocardiographic criteria. RESULTS: PVT was observed in 80.5% of patients, MVT in 16.9%, and both in 2.6%. Patients with MVT tended to be older, exhibit drug-induced Brugada electrocardiogram, and were more frequently White. Pause-dependent initiation occurred in approximately 25% of PVT and approximately 33% of MVT episodes. Coupling intervals initiating PVT were nonsignificantly shorter than for MVT (median 368 milliseconds vs 395 milliseconds), with a significantly lower prematurity index and faster early arrhythmia cycle length. Antecedent premature ventricular complexes were present in approximately 43% of both VTA types, commonly sharing morphology with the initiating premature ventricular complex. The prevalence of pathogenic/likely pathogenic SCN5A mutation did not differ between groups. CONCLUSIONS: In this largest analysis to date of spontaneous VTA onset in BrS, MVT occurred in a substantial minority and was associated with older age, White ethnicity, drug-induced electrocardiogram pattern, and a preceding tachycardia. Initiation patterns were broadly similar across arrhythmia types, although PVT exhibited a significantly lower prematurity index and faster early cycle length despite only nonsignificant shorter coupling intervals. These findings refine the clinical and electrophysiological characterization of BrS-related arrhythmias and delineate distinct features of PVT and MVT initiation.

Adult↗
PubMed2007

Fine-needle aspiration biopsy-RT-PCR expression analysis of prothymosin alpha and parathymosin in thyroid: novel proliferation markers?

Fine-needle aspiration biopsy-based cytology has become an established and reliable diagnostic preoperative test in the evaluation of thyroid nodules. Despite the high specificity and sensitivity of the method, results might be doubtful in a significant number of cases. Genetic analysis of the aspirates by RT-PCR may contribute, in parallel to the cytology report, to a more precise diagnosis. Prothymosin alpha and parathymosin are two homologous chromatin remodeling proteins essential for cell cycle progression and proliferation of either normal or malignant cells. A semi-quantitative RT-PCR assay was developed to determine prothymosin alpha and parathymosin mRNA expression patterns in thyroid follicular cells obtained from the fine-needle aspiration biopsy specimens of patients diagnosed with simple nodular goitre, follicular adenoma, papillary and follicular well-differentiated carcinomas. Prothymosin alpha and parathymosin mRNA levels were found significantly elevated in well-differentiated carcinomas in relation to adenomas (p<0.05) and goitres (p<0.05), an event possibly linked to the proliferation activity of thyroid follicular cells. Further studies are required to establish prothymosin alpha and parathymosin as diagnostic proliferation markers in thyroid cancer, especially in cases of undetermined cellular morphology of follicular origin which reflect the most common cytohistopathological discrepancies.

Adenocarcinoma, Follicular↗
PubMed2006

ST-segment elevation induced during the transseptal procedure for radiofrequency catheter ablation of atrial fibrillation.

We report two cases of transient coronary artery ischemia manifested as chest discomfort with ST-segment elevation in inferior leads during the transseptal procedure for radiofrequency catheter ablation of atrial fibrillation. This unexpected complication was resolved by intravenous administration of nitrates. All patients exhibited normal coronary arteries in angiography. A neurally mediated pathway activated by the mechanical effects of the transseptal puncture on the interatrial vagal network leading to coronary artery spasm may be considered as a possible explanation of this phenomenon. Coronary artery embolism following the transseptal procedure represents a different underlying mechanism.

Atrial Fibrillation↗
PubMed2006

Secondary prevention of sudden cardiac death in coronary artery spasm: is implantable cardioverter defibrillator always efficient?

Syncope and/or cardiac arrest in the setting of coronary artery spasm have been associated with atrioventricular block and asystole or ventricular tachyarrhythmias. Ventricular arrhythmias have been predominantly reported in cases of multivessel coronary artery spasm. The present report highlights the case of a young woman who suffered repeated episodes of multivessel coronary artery spasm in association with polymorphic ventricular tachycardia and cardiac arrest. The efficacy of implantable cardioverter defibrillator in secondary prevention of sudden cardiac death due to coronary artery spasm is discussed.

Adult↗
PubMed2006

Swimming-triggered aborted sudden cardiac death in a patient with Andersen-Tawil syndrome.

In this report we describe the case of a 42-year-old woman who experienced an episode of near drowning during recreational swimming. A diagnosis of Andersen-Tawil syndrome was made based on the patient's dysmorphic features, characteristic T-U-wave patterns and ventricular arrhythmias. To our knowledge, this is the first report of a swimming-triggered cardiac event in a patient with Andersen-Tawil syndrome.

Adult↗
PubMed2006

Open ended circulation pattern: a rare case of a protective coronary artery variation and review of the literature.

Persistent intercoronary communications, forming the so-called open ended coronary circulation pattern, are rare findings of coronary angiography. A case of intercoronary connection between the left anterior descending artery (LAD) and the right coronary artery (RCA), with an obstructive lesion, and no evidence of myocardial infarction is presented. This is an exceptional variant, only 20 cases of which were found in the literature. The potential protective role of this anomaly against occlusive coronary artery disease is discussed and similar reports are reviewed.

Aged↗
PubMed2006

Enterovirus-induced fulminant myocarditis and hemophagocytic syndrome.

We report the case of a 17-year-old male who was admitted to the emergency department in cardiogenic shock and multiorgan failure due to fulminant myocarditis. The following days the patient developed anemia, thrombocytopenia, and hepatosplenomegaly. Bone marrow examination showed many mature histiocytes with active hemophagocytosis. Nested reverse transcriptase-PCR molecular analysis of blood samples and sequencing of the amplified alleles confirmed enteroviral infection. Our patient was treated with inotropic agents and immunoglobulin, and recovered completely. This is the first report that documents concomitant presentation of fulminant myocarditis and hemophagocytic syndrome due to enteroviral infection.

Adolescent↗
PubMed2006

Early repolarization syndrome: is it always benign?

Early repolarization syndrome is a well-recognized idiopathic electrocardiographic phenomenon characterized by prominent J wave and ST-segment elevation predominantly in left precordial leads. The syndrome shares remarkable cellular, ionic, and electrocardiographic similarities with the Brugada syndrome and idiopathic ventricular fibrillation (a variant of the Brugada syndrome with ST-segment elevation in inferior leads). Although early repolarization syndrome is considered a benign entity, its arrhythmogenic potential still remains unknown. We report the case of a 39-year-old male with a family history of sudden death and an electrocardiogram consistent with early repolarization syndrome. Diagnostic dilemmas are discussed.

Adult↗
PubMed2006

Pathophysiology and management of syncope in Kearns-Sayre syndrome.

A 20-year-old woman with known Kearns-Sayre syndrome was transferred to the emergency department due to syncopal episodes. The electrocardiogram on admission showed complete atrioventricular block. The diagnosis of mitochondrial encephalomyopathy was made when she was 14 years old. At the time of the initial diagnosis, she displayed a normal electrocardiogram pattern. At the age of 17, electrocardiogram recordings demonstrated right bundle branch block with left anterior fascicular block and a prolonged QTc interval of 485 milliseconds (Figure). She was taking coenzyme Q10, oral nicotinamide adenine dinucleotide (reduced), piribedil, amantadine, and primidone. Transthoracic echocardiography revealed normal wall motion of both ventricles and mitral valve prolapse without regurgitation. A permanent dual-chamber pacemaker was immediately implanted.

Adult↗
PubMed2006

Acute myocardial infarction with normal coronary arteries in a patient with Hodgkin's disease: a late complication of irradiation and chemotherapy.

We describe the case of a 31-year-old man who experienced an acute myocardial infarction 16 years after undergoing radiation and vinca alkaloid therapy for Hodgkin's disease. Even though coronary artery disease is a well-established complication after mediastinal radiation therapy, this adult patient had normal coronary angiographic results, with no traditional risk factors for coronary artery disease, and no hematologic or other abnormality associated with hypercoagulability.

Acute Disease↗
PubMed2005

Hypertrophic cardiomyopathy in a patient with Crohn's disease: a case report.

Cardiac manifestations of Crohn's disease are rare; the most common is pericarditis. In the present report we briefly describe a 56-year-old man with Crohn's disease who presented to the emergency department due to paroxysmal atrial flutter. A transthoracic echocardiographic study revealed asymmetric left ventricular hypertrophy without outflow pressure gradient. Reviewing the literature, hypertrophic cardiomyopathy has not been previously described in patients with Crohn's disease.

Cardiomyopathy, Hypertrophic↗
PubMed2005

QT interval prolongation and torsade de pointes associated with indapamide.

Direct blockade of the delayed rectifier repolarising potassium current is the major underlying mechanism of drug-induced QT interval prolongation. Indapamide is a well known blocker of the slow component of the delayed rectifier current leading to prolongation of cardiac repolarization. The case of an acquired long QT and torsade de pointes ventricular tachycardia in a woman with systemic lupus erythematosus and hypertension receiving prednisolone and indapamide, respectively, is described in the present report.

Adult↗
PubMed2005

Spontaneous coronary artery dissection associated with oral contraceptive use: a case report and review of the literature.

Spontaneous coronary artery dissection (SCAD) represents a rare cause of acute coronary syndromes with complex pathohysiology. We briefly describe a 50-year-old woman, without traditional cardiovascular risk factors, hospitalized for an acute ST-elevation myocardial infarction and treated with thrombolytic therapy. Notably, the patient was on oral contraceptives for the past 10 years. Coronary angiography showed a dissection of the distal left anterior descending artery. She was treated conservatively and her clinical status improved without evidence of continuing ischemia, while a repeated catheterization 6 months later showed a complete resolution of the dissection. It has been speculated that the female hormones may be responsible for the increased incidence of SCAD among women particularly during the peripartum period or during the exogenous administration of such agents. A systematic review of the literature revealed 4 further cases reporting an association of SCAD with oral contraceptive use.

Aortic Dissection↗
PubMed2005

Exercise-induced second-degree atrioventricular block.

In this report we describe the case of a 56-year-old woman with normal 1:1 AV conduction at rest who developed 2:1 AV block during treadmill exercise testing. Electrophysiological study documented 2:1 AV block proximal to the His bundle with reappearance of 1:1 AV conduction at a higher pacing atrial rate. A gap phenomenon involving a proximal and distal part of the AV node may be a likely explanation of paradoxical AV conduction in our case.

Bundle of His↗
PubMed2005

Drug-induced QT interval prolongation after ciprofloxacin administration in a patient receiving olanzapine.

Several non-antiarrhythmic drugs including antibiotic and antipsychotic agents have been shown to prolong cardiac repolarization predisposing to torsade de pointes ventricular tachycardia. Blockade of the delayed rectifier (repolarising) potassium current and drug interactions with inhibitors of the CYP-mediated metabolism are the most common underlying mechanisms. In the present case report, an elderly woman receiving a long-term medication with azathioprine, olanzapine and valsartan developed a marked QT interval prolongation after intravenous administration of ciprofloxacin.

Aged↗