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The patient with acute cardiovascular problems
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
The cardiac conduction system is comprised of conduction cells. These cells are able to generate their own impulse, known as auto-rhythmic cells. They are responsible for the production and transmission of electrical waves that cross the heart and stimulate the myocardium to contract. The conduction cells do not contract themselves but purely provide the stimulus for adjacent myocardial cells to do so. The conduction system is illustrated in Figure 6.4.
Isolated Atrial Preparations
Published in John H. McNeill, Measurement of Cardiac Function, 2020
M.K. Pugsley, E.S. Hayes, M.J.A. Walker
The right atrium contains many important anatomical structures necessary for cardiac conduction and coronary circulation (see Figure 1). The sinoatrial node, which lies near the junction of the right atrium and the superior vena cava, is responsible for pacemaker activity in the heart.
Bradycardia
Published in Andrea Natale, Oussama M. Wazni, Kalyanam Shivkumar, Francis E. Marchlinski, Handbook of Cardiac Electrophysiology, 2020
Bradyarrhythmias and conduction blocks are common electrocardiographic findings. These arrhythmias can result from a wide variety of disorders of the cardiac conduction system. Bradycardias are generally divided into disorders involving either the sinus node or atrioventricular conduction or as neurally mediated arrhythmias. Bradyarrhythmias may be discovered as incidental electrocardiographic abnormalities or may be found after investigation for symptoms suggestive of their presence. A wide variety of symptoms may be caused by the different etiologies of bradycardia, often times adding diagnostic difficulty to patients with coexisting medical problems.
Management of congenitally corrected transposition from fetal diagnosis to adulthood
Published in Expert Review of Cardiovascular Therapy, 2023
Due to abnormal position of the atrioventricular node and its connection to the atrioventricular bundle in ccTGA, cardiac conduction disorders are common and permanent pacemaker therapy is frequently required [27]. Unless contraindicated (patient’s size, unrepaired associated lesions), the transvenous system can be implanted. Subpulmonary univentricular pacing was shown to be associated with deterioration of sRV and exacerbation of tricuspid valve regurgitation [59,60]. Study on 53 patients with dual-chamber univentricular pacemakers revealed an improvement after upgrading to biventricular pacing [60]. However, some observations provided different results [61]. Transvenous implantation of an sRV lead is possible in ccTGA patients with suitable anatomy assessed by advanced cardiac imaging [62]. Alternatively, surgical placement of ventricular pacing leads or a hybrid approach can be performed. According to Pediatric and Congenital Electrophysiology Society (PACES) and Heart Rhythm Society guidelines, cardiac resynchronization therapy (CRT) can be useful for adults with sRV function ≤35%, sinus rhythm, complete right bundle branch block with QRS ≥150 ms (spontaneous or paced) and NYHA class II-IV [63]. The benefit of CRT in patients with sRV dysfunction without conduction disturbances is unclear.
Electrocardiographic changes after breast reduction surgery
Published in Journal of Plastic Surgery and Hand Surgery, 2023
Ayca Ergan Sahin, Tugce Yasak, Burak Yılmaz, Ahmet Anil Sahin, Ali Rıza Demir, Ozlem Colak
In a study, it was found that breast implants might interpret the ECG readings, thus the records might mislead the clinician [22]. In this study, the major limitation was high inter-observer variability between the reviewers of the ECGs. In another study, Kramer et al. found that breast reconstruction surgery employing with tissue expanders did not interfere with the ECG recordings [23]. In this study, all patients had breast cancer and reconstruction surgeries performed because of their malignant pathology. Cancer and related therapies such as radiotherapy or chemotherapy might themselves affect the ECG recordings. Our study is unique that only evaluates the ECG recordings after BRS without any additional pathologies such as cancer or any other systemic disease and specifically inspects the affect of surgery and thoracic changes after the surgery in ECG recordings. Another important point of our study was the patient population that only included patients who had BRS with the indication for habitual or postural changes in the patients and not for aesthetical purposes that indeed might directly indicate the findings related to thoracic postural changes after the surgeries. According to present knowledge, improvement in atrial and ventricular conduction is associated with decreased arrhythmogenesis in cardiac conduction. Therefore, in our study, we believe that these changes occurred due to the improved posture and habitus of the patients and increased pulmonary functions after BRS.
The White Panther – Rare exposure to Amanita multisquamosa causing clinically significant toxicity
Published in Clinical Toxicology, 2021
V. Vohra, I. V. Hull, K. T. Hodge
Scant literature exists surrounding Amanita multisquamosa exposures. Toxicity has been compared to Amanita muscaria ingestion, with primarily neurological features and mild gastrointestinal (GI) effects [2,3]. Previous cases include a Canadian family who experienced GI symptoms and demonstrated erratic behavior three hours after eating cooked specimens, resembling Amanita muscaria toxicosis [3]. High concentrations of ibotenic acid and muscimol have been found in Amanita multisquamosa samples, supporting comparisons to Amanita muscaria [4]. Ibotenic acid exerts excitatory central nervous system (CNS) effects while muscimol produces CNS depression [5]. Symptoms may appear within 30–120 min and can last 10–24 h [4,5]. Symptomatic and supportive care is indicated [5]. Our patient had a cardiac conduction abnormality of unknown etiology. Comprehensive molecular characterization of other toxins in Amanita multisquamosa has not been elucidated, therefore this exposure cannot be ruled out as a potential cause.