- [Dual atrioventricular nodal pathways: physiology, arrhythmic findings, and electrocardiographic manifestations]. [Journal Article]
- GIG Ital Cardiol (Rome) 2018; 19(4):222-231
- The atrioventricular (AV) node is an anatomically well-defined structure, conveniently housed in the triangle of Koch. There are two distinct atrial impulse approaches to the AV node, one of which (i...
The atrioventricular (AV) node is an anatomically well-defined structure, conveniently housed in the triangle of Koch. There are two distinct atrial impulse approaches to the AV node, one of which (in the anterior portion of triangle of Koch) has a faster conduction, while the other one (in the posterior portion) has a slower conduction. However, it is not said that such a conductive duality translates into any arrhythmic phenomena. Actually, these arrhythmias are due to an imbalance of the two pathways electrophysiological properties, which does not always exist. In the presence of such an imbalance, the dual AV nodal physiology is, however, the substrate for various arrhythmias and curious electrocardiographic behaviors. Often the fast pathway is characterized by a relatively long refractory period. In contrast, the slow approach is often characterized by shorter refractoriness.The unbalanced refractoriness of the two nodal pathways constitutes the prerequisite for the most common form of paroxysmal supraventricular tachycardia: the AV nodal reentrant tachycardia (AVNRT). In subjects prone to this type of arrhythmia, during sinus rhythm, nodal conduction usually occurs from the anterior approach (fast pathway). However, a premature atrial beat may find this pathway refractory and cross the AV node through the posterior approach (slow pathway), resulting in a sudden prolongation of the AV conduction time ("jump"). This allows the impulse, once it reaches the common end, to excitate the fast pathway in a retrograde direction and to return backwards to the atrium, thus triggering a circus movement that can result in a "slow-fast" AVNRT. More rarely, an AVNRT can take place in an opposite direction of the reentrant impulse ("fast-slow" variety of AVNRT). A paroxysmal supraventricular tachycardia may seldom occur with a regularly alternating RR cycle, if the reentrant mechanism involves retrogradely an accessory AV pathway and, in anterograde direction, a fast and a slow AV nodal pathway, alternately. Among the mechanisms underlying the total RR irregularity during atrial fibrillation, there is probably also the possibility that the AV node may offer to the atrial impulses two distinct pathways to reach the His bundle. Not too rarely, a dual AV nodal physiology can occur during sinus rhythm, through unexpected and sudden changes in the AV conduction time, so that two distinct PR families can be observed. It is likely that the presence of dual AV nodal pathways can facilitate or promote a Wenckebach conduction mechanism at nodal site.
- Surgical linear ablation for ventricular tachycardia with postinfarction ventricular aneurysm. [Journal Article]
- JSJ Surg Res 2018; 228:211-220
- CONCLUSIONS: Surgical linear endo-epicardial ablation seemed to be feasible in a porcine model with VT and LVA.
- Acute Pericarditis as a Presentation of Adrenal Insufficiency. [Journal Article]
- CCureus 2018 Apr 13; 10(4):e2474
- Acute pericarditis as a presenting sign of adrenal insufficiency is rarely reported. We present a rare case that highlights pericarditis as a clinical presentation of secondary adrenal insufficiency ...
Acute pericarditis as a presenting sign of adrenal insufficiency is rarely reported. We present a rare case that highlights pericarditis as a clinical presentation of secondary adrenal insufficiency later complicated by cardiac tamponade. A 44-year-old lady who presented to the hospital with a one-day history of pleuritic chest pain and shortness of breath. In the emergency room, she had a blood pressure of 70/35 mmHg. Laboratory evaluation revealed white blood cell count of 16.08 k/cumm with neutrophilia, normal renal function and elevated troponin (0.321 ng/mL, normal 0.000-0.028). An electrocardiogram (EKG) showed sinus tachycardia, low voltage, PR suppression and ST changes consistent with acute pericarditis. Echocardiogram showed small pericardial effusion without tamponade physiology. Infectious workup was negative; she was thought to have acute adrenal insufficiency likely secondary to viral pericarditis. We treated the patient with high dose nonsteroidal anti-inflammatory drugs (NSAIDS) and hydrocortisone. Three weeks later, she presented to emergency room with complaints of persistent nausea, vomiting, chills, weakness. Her blood pressure was 49/23 mmHg. Random serum cortisol level was <1.2 mcg/dl (normal A.M. specimens 3.7-19.4 mcg/dl). Echocardiogram showed loculated pericardial fluid adjacent to the right ventricle with echocardiographic evidence of tamponade. Emergent pericardiocentesis yielded 250 ml of straw color fluid. Blood pressure improved after the procedure. The patient was initially started on IV stress dose steroids, but following clinical stabilization, hydrocortisone was switched to a physiological dose of 15 mg in am and 10 mg in pm. Although the mechanism of pericarditis in adrenal failure is unknown, this clinical presentation may help early diagnosis of adrenal failure and pericarditis. Early recognition and prompt treatment of this rare presentation are critical to prevent morbidity and mortality.
- Rapid calcium loss may cause arrhythmia in hemofiltration with regional citrate anticoagulation: a case report. [Journal Article]
- BNBMC Nephrol 2018 Jun 14; 19(1):136
- CONCLUSIONS: This case indicated that rapid calcium loss may cause arrhythmia in RCA-hemofiltration, and the rate of net calcium loss should be limited below a threshold value to prevent similar adverse effect during RCA-RRT.
- When a Pseudo-Infarct Electrocardiogram (ECG) Pattern in a Posterior Accessory (Wolff-Parkinson-White) Pathway Masks a True Inferior Infarct. [Journal Article]
- AJAm J Case Rep 2018 Jun 13; 19:685-688
- CONCLUSIONS: The presence of pseudo-infarct pattern due to a WPW does not always preclude the presence of underlying true infarct pattern, especially in the presence of coronary artery disease risk factors.
- Five-year outcome and predictors of success after second-generation cryoballoon ablation for treatment of symptomatic atrial fibrillation. [Journal Article]
- IJInt J Cardiol 2018 Sep 01; 266:106-111
- CONCLUSIONS: Sinus rhythm was maintained in a substantial proportion of patients even 5 years after CB-Adv ablation. Patients with a non-enlarged left atrium without diabetes had the best outcome.
- Dangerous mistake: an accidental caffeine overdose. [Journal Article]
- BCBMJ Case Rep 2018 Jun 08; 2018
- Caffeine (1,3,7-trimethylxanthine) is a natural product commonly presented in food's composition, beverages and medicinal products. Generally, it is thought to be safe under normal dosage, yet it can...
Caffeine (1,3,7-trimethylxanthine) is a natural product commonly presented in food's composition, beverages and medicinal products. Generally, it is thought to be safe under normal dosage, yet it can be fatal in case of severe intoxication. We report a case of a healthy 32-year-old woman who went to the local emergency department (ED) 30 min after ingesting, accidentally, 5000 mg of anhydrous caffeine for a preworkout supplement. At the ED, she presented an episode of presyncope followed by agitation. ECG showed polymorphic broad complex QRS tachycardia and arterial blood gas revealed metabolic acidaemia with severe hypokalemia. The dysrhythmia was successfully treated with intravenous propranolol. Acid-base and hydroelectrolytic disorders were also corrected. A persistent sinus tachycardia was observed in the first 2 days in the ward and 5 days later she was discharged asymptomatic with internal medicine follow-up.
- Management of acquired bronchopleural fistula due to chemical pneumonia. [Journal Article]
- CJCi Ji Yi Xue Za Zhi 2018 Apr-Jun; 30(2):116-118
- Bronchopleural fistula (BPF) is a sinus tract between the bronchus and the pleural space that may result from a necrotizing pneumonia/empyema (anaerobic, pyogenic, tuberculous, or fungal), lung neopl...
Bronchopleural fistula (BPF) is a sinus tract between the bronchus and the pleural space that may result from a necrotizing pneumonia/empyema (anaerobic, pyogenic, tuberculous, or fungal), lung neoplasms, and blunt and penetrating lung injuries or may occur as a complication of procedures such as lung biopsy, chest tube drainage, thoracocentesis, or radiation therapy. The diagnosis and management of BPF remain a major therapeutic challenge for clinicians, and the lesion is associated with significant morbidity and mortality. Here, we present a 70-year-old male with acquired BPF due to chemical pneumonitis caused by aspiration of kerosene who presented with the symptoms of fever, cough with expectoration, breathlessness and signs of tachycardia, tachypnea, diminished breath sounds, and crepitations. After a 3-week course of culture-sensitive antibiotics with β-lactam and β-lactamase inhibitors, open drainage of the empyema was done following which the patient showed symptomatic improvement and was discharged.
- Insights on the pulmonary artery-derived ventricular arrhythmia. [Review]
- JCJ Cardiovasc Electrophysiol 2018 Jun 04
- Pulmonary artery-derived ventricular arrhythmia is gradually being recognized, which in a clinical context is recognized as an arterial ectopic beat. Our study aimed to provide new insights on the ep...
Pulmonary artery-derived ventricular arrhythmia is gradually being recognized, which in a clinical context is recognized as an arterial ectopic beat. Our study aimed to provide new insights on the epidemiological characteristics, origin site, electrocardiogram (ECG) characteristics, intra-cardiac electrophysiological characteristics and radiofrequency catheter ablation (RFCA) strategies for pulmonary artery-derived ventricular arrhythmia. Patients with a distance between the origin site and the pulmonary valve of > 10 mm have what is known as pulmonary trunk-derived ventricular arrhythmia, while patients with a distance between the origin site and the pulmonary valve of ≤10 mm have what is known as pulmonary sinus cusp-derived ventricular arrhythmia. It is very difficult to differentiate pulmonary artery-derived ventricular arrhythmia from right ventricular outflow tract-derived ventricular arrhythmia on ECGs as both share similar anatomical features, but pulmonary artery-derived ventricular arrhythmia shows obvious intra-cardiac electrophysiological characteristics. Currently, conclusions based on the epidemiological characteristics of pulmonary artery-derived ventricular arrhythmia, relationship between the origin site and the pulmonary valve, electrophysiological characteristics, and RFCA strategies are controversial and still need further study. This article is protected by copyright. All rights reserved.
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- Prognostic Value of Electrocardiography in Patients With Fulminant Myocarditis Supported by Percutaneous Venoarterial Extracorporeal Membrane Oxygenation - Analysis From the CHANGE PUMP Study. [Journal Article]
- CJCirc J 2018 Jun 01
- CONCLUSIONS: In patients with FM, CAVB and VT/VF carried a higher risk of in-hospital death. Wide QRS also predicted a higher risk of in-hospital death in patients with SR.