Case 23: Heart and Lungs
Layne Kerry, Janice Rymer in 100 Diagnostic Dilemmas in Clinical Medicine, 2017
The patient's thyrotropin (TSH) level should be measured to identify hyperthyroidism. An electrocardiogram (ECG) will show whether the patient is in sinus rhythm, atrial fibrillation, or another arrhythmia at present. Continuous cardiac monitoring will be more beneficial in identifying an abnormal rhythm that only occurs intermittently. A chest x-ray should be performed to look for evidence of infection including tuberculosis, or a lung mass. If pneumonia is seen then antibiotic therapy can be commenced. If there is no obvious infection then a computed tomography (CT) scan of the chest may be considered to look for malignancy, possibly in addition to a scan of the abdomen and pelvis to identify sites of metastatic spread. If a lung mass is visualised on CT imaging then a sample of abnormal tissue or cells may be obtainable via bronchoscopy or CT-guided biopsy for histological analysis.
Case 28
Edward Schwarz, Tomos Richards in Cases of a Hollywood Doctor, 2019
The ECG demonstrates a sinus rhythm, with a rate of approximately 65. There is no axis deviation. There is ST elevation in leads II, III and aVF (inferior leads) and ST depression in leads I and aVL (lateral leads). ST elevation of more than 1 mm in two or more consecutive chest leads or 2 mm in two or more limb leads is diagnostic of an ST elevation myocardial infarction.
Physiological consequences of ionic mechanisms
Burt B. Hamrell in Cardiovascular Physiology, 2018
This is the normal pacemaker of the heart because diastolic depolarization is faster than in before AV node cells and much before Purkinje fibers (self-study module Cardiac Action Potentials, Part 2: Nodal and Conduction System Myocytes). The pacemaker potential in SA node cells normally reaches threshold before the AV node cells and much before Purkinje fibers. The normal heart rhythm, driven by the SA node as the pacemaker, is called “normal sinus rhythm.”The intrinsic frequency of the SA node, in the absence of input from the autonomic nervous system, is about 100 beats/min.
The quest for indicators of paroxysmal atrial fibrillation in sinus rhythm – the DETECT AF trial
Published in Acta Cardiologica, 2019
N. Brasier, S. Engelter, T. Kolbitsch, A. Tabord, J. Knobeloch, M. Kühne, D. Conen, C. Traenka, T. Kreutzberger, G. Völlmin, J. Eckstein
Background: Atrial fibrillation (AF) is related to an increased stroke risk. At present, differentiation between patients with paroxysmal AF (pAF) and without is only possible during AF episodes and not during sinus rhythm. If AF could be diagnosed more quickly and reliably, anticoagulation therapy may be administered and prevent from cardioembolic strokes. The DETECT AF trial evaluated the hypothesis that propagation of electric activities in patients with pAF differs from propagation in healthy atria and that this can be detected with a three-dimensional electrocardiogram in patients during sinus rhythm. Methods: We conducted a case-control study including patients with a history of pAF and a control group with no history of AF. Vectorcardiographic beat-to-beat variability of atrial activation in sinus rhythm was tested and compared between the two groups. Results: One hundred and eight patients with a history of pAF in sinus rhythm and 121 controls in sinus rhythm were included. With a combination of specific vectorcardiographic beat-to-beat variability parameters discrimination between the two groups was possible with a specificity of 82% and a sensitivity of 71% (p≤.01). Using heart rate independent parameters, both specificity and sensitivity were reduced to 70%. Conclusions: Analysis of atrial vectorcardiographic beat-to-beat variability indicates that atrial conduction variability in patients with pAF differs from patients without AF and may be used as an indicator to estimate the risk for pAF in patients during sinus rhythm. Further studies to investigate the potential of this parameter are needed. Trial registration: ClinicalTrials.gov identifier: NCT02270112.
Mean platelet volume, an indicator of platelet activation, is increased in patients with mitral stenosis and sinus rhythm
Published in Scandinavian Journal of Clinical and Laboratory Investigation, 2009
Ercan Varol, Mehmet Ozaydin, Yasin Türker, Sule Alaca
Systemic thromboembolism is a serious major complication in patients with mitral stenosis. However, the pathogenesis of thromboembolism in mitral stenosis is not fully understood. Previous studies have demonstrated that platelet activation occurs in serum of patients with rheumatic mitral stenosis (MS). The aim of this study was to assess the mean platelet volume (MPV), an indicator of platelet activation, in patients with MS. The study group consisted of 36 patients with MS who were in sinus rhythm. An age and gender matched control group was composed of 30 healthy volunteers. We measured serum MPV values in patients and control subjects. MPV was significantly higher among MS patients with sinus rhythm (SR) when compared with the control group (9.2±1.4 vs 8.1±0.9 fl respectively; p
Improving ablation strategies for the treatment of atrial fibrillation
Published in Expert Review of Medical Devices, 2014
Jason G Andrade, Laurent Macle
Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. The contemporary management of AF is centered on symptomatic improvement, as well as reduction in the AF associated morbidity and mortality. For many highly symptomatic patients catheter ablation offers an efficacious means to maintaining sinus rhythm when antiarrhythmic drugs have been ineffective, are contraindicated or cannot be tolerated. Over the past 15 years, catheter ablation has moved from an ‘experimental therapy’ to the standard of care for the maintenance of sinus rhythm. Unfortunately, while the results of ablation are unequivocally superior to medical therapy, recognized limitations of the contemporary AF ablation procedures have spurred several developments designed to improve the efficacy of the index ablation procedure, while limiting adverse events. The purpose of this review is to discuss the procedural refinements, and technological innovations proposed to outcomes of patients undergoing a percutaneous catheter ablation procedure for AF.