The Electrophysiology of Atrial Fibrillation: From Basic Mechanisms to Catheter Ablation.

The electrophysiology of atrial fibrillation (AF) has always been a deep mystery in understanding this complex arrhythmia. The pathophysiological mechanisms of AF are complex and often remain unclear despite extensive research. Therefore, the implementation of basic science knowledge to clinical practice is challenging.

Incidence, electrophysiological characteristics, and long-term follow-up of perimitral atrial flutter in patients with previously confirmed mitral isthmus block.

Introduction: After mitral isthmus (ΜΙ) catheter ablation, perimitral atrial flutter (PMF) circuits can be maintained due to the preservation of residual myocardial connections, even if conventional pacing criteria for complete MI block are apparently met (MI pseudo-block). We aimed to study the incidence, the electrophysiological characteristics, and the long-term outcome of these patients.

Methods: Seventy-two consecutive patients (mean age 62.

Ventricular ectopy from the non-coronary cusp: Pathophysiological and anatomical considerations.

Non-coronary cusp (NCC) is a rare site for ventricular arrhythmias because it does not come into direct contact with the ventricular myocardium. Instead, the NCC comes in contact with the membranous septum near the His region. We describe a case of a young man with a ventricular ectopy who was successfully ablated in the NCC.

Impact of early vs late postoperative radioiodine remnant ablation on final outcome in patients with low-risk well-differentiated thyroid cancer.

Objective: Postoperative radioiodine remnant ablation (RRA) represents an adjunctive therapeutic modality in patients with differentiated thyroid cancer (DTC). The impact of late vs early RRA on the outcome of DTC is currently unclear. The aim of the study was to evaluate the outcome of patients with DTC according to RRA timing.

Health status of Greek thyroid cancer patients after radioiodine administration compared to a demographically matched general population sample.

The impact of radioiodine-131 ((131)I) treatment on thyroid cancer patients' quality of life is controversial. We conducted a cross-sectional study of 60 patients aged 18-73 years old who had recently underwent near total thyroidectomy due to papillary thyroid cancer and were scheduled for (131)I treatment. On admission to our department, prior to (131)I administration patients underwent clinical and laboratory investigation including routine clinical biochemistry, thyroid stimulating hormone (TSH) and thyroglobulin (Tg) measurements.

Glucose homeostasis in patients with acromegaly treated with surgery or somatostatin analogues.

Objective: Long-acting somatostatin analogues (SSA) are widely used for the treatment of acromegaly; however, they also alter β-cell function by inhibiting insulin secretion. In this study, we assess the effect of SSA on glucose homeostasis in patients with acromegaly treated with SSAs, compared to patients treated with surgery.

Design: We studied four groups of patients with acromegaly: at the time of diagnosis (group I, n = 53), after successful transsphenoidal surgery (TSS, group II, n = 30) and under successful SSA treatment (group III, n = 20); 22 patients were studied only before treatment, 19 only post-treatment, while 31 patients (group IV) were studied before and after the treatment.

The effect of body mass index on the diagnosis of GH deficiency in patients at risk due to a pituitary insult.

Objectives: Diminished GH response to stimulation has been demonstrated in obesity, leading to erroneous diagnosis of GH deficiency. The aim of this study was to evaluate the influence of body mass index (BMI) on GH responsiveness in patients at risk for pituitary function deficits.

Methods: A total of 59 healthy subjects and 75 patients with a pituitary insult underwent insulin tolerance test or pyridostigmine+GHRH test in order to assess GH secretory reserve.

Atrioventricular re-entrant and ventricular tachycardias of left origin: a rare combination.

The simultaneous occurrence of atrial and ventricular tachycardias, or junctional and ventricular tachycardias, has been reported previously. We report on a patient presenting with syncope and demonstrating, simultaneously, atrioventricular re-entrant tachycardia and ventricular tachycardia of left origin. A left lateral concealed pathway was responsible for the former arrhythmia, while the latter arrhythmia was located in the anterolateral wall of the left ventricle.

Iodine 131 treatment for differentiated thyroid carcinoma in patients with end stage renal failure: dosimetric, radiation safety, and practical considerations.

Background: Iodine 131 ablation following total thyroidectomy is considered an indispensable element of successful treatment of differentiated thyroid carcinoma (Dtc). because of the essential role of the kidneys in iodine clearance, (131)I therapy of Dtc in patients with end stage renal disease, particularly those maintained on haemodialysis, present a number of special features: the (131)I activity needs to be modified, the haemodialysis sessions need to be adjusted at the time of (131)I therapy, and there are radiation safety considerations during dialysis. there is considerable controversy over these crucial questions in the reports published so far in the literature, which concern a total of fourteen patients.

Torsades de pointes as a cause of sudden death in a patient with aortic stenosis and atrial fibrillation.

The occurrence of sudden cardiac death during Holter monitoring in patients with aortic stenosis has been reported previously. In the majority of the reported cases, the cause of death was a malignant ventricular tachyarrhythmia. The presence of a strong association between frequency and complexity of ventricular arrhythmias and sudden death in patients with aortic stenosis has been proposed.

Electroanatomical mapping and ablation of upper loop reentry atrial flutter.

Upper loop reentry is a rare type of non isthmus-dependent atrial flutter with a reentry circuit around the superior vena cava. We present a case of atrial flutter of this type in a 75-year-old man with concomitant sick sinus syndrome. The diagnostic approach used three-dimensional electroanatomical mapping with the upgraded ENSITE 3000 system.

Increased plasma plasminogen activator inhibitor-1 levels: a possible marker of hypertensive target organ damage.

High plasma plasminogen-activator inhibitor-1 (PAI-1) concentrations have been reported in coronary artery disease and stroke. We therefore, prospectively studied the association of PAI-1 with early target organ damage in patients with arterial hypertension has not been clearly established. We therefore investigated 136 subjects, 64 males and 72 females, mean age 50.