China
Africa
Explore chapters and articles related to this topic
Supraventricular rhythms
Published in Andrew R Houghton, Making Sense of the ECG, 2019
Conduction of impulses between the atria and the ventricles can normally only occur via one route, the AV node. However, some individuals have an additional connection between the atria and the ventricles, known as an accessory pathway. A left-sided accessory pathway, between the left atrium and left ventricle, is shown in Figure 7.12; however, accessory pathways can occur virtually anywhere in the annulus fibrosus, the fibrous ring separating the atria from the ventricles.
Supraventricular tachyarrhythmias in the elderly
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
Jason T. Jacobson, Sei Iwai, Ali Ahmed, Wilbert S. Aronow
DC cardioversion should be performed if a rapid ventricular rate in patients with paroxysmal AF associated with WPW syndrome is life-threatening or fails to respond to drug therapy. Drug treatment for PAF associated with WPW syndrome includes procainamide, disopyramide, quinidine (139), and ibutilide. Adenosine, beta-blockers, digoxin, IV amiodarone, diltiazem, and verapamil are contraindicated in patients with AF with WPW syndrome because these drugs shorten (directly or indirectly) the refractory period of the accessory AV pathway, resulting in more rapid conduction down the accessory pathway. This results in a marked increase in ventricular rate, potentially degenerating to ventricular fibrillation (VF). Radiofrequency catheter ablation or surgical ablation of the accessory conduction pathway should be considered in patients with AF and rapid AV conduction over the accessory pathway (140). In 500 patients with an accessory pathway, radiofrequency catheter ablation of the accessory pathway was successful in 93% of patients (141).
Electrocardiography and arrhythmias
Published in Neil Herring, David J. Paterson, Levick's Introduction to Cardiovascular Physiology, 2018
Neil Herring, David J. Paterson
The unforgettably named Wolff-Parkinson-White syndrome comprises episodes of paroxysmal tachycardia, resulting from an anatomically definable re-entry pathway, the accessory bundle of Kent. This is an extra electrical connection across the annulus fibrosus, additional to the bundle of His. The re-entry circuit can form with anterograde conduction down the bundle of Kent and back up the AV node (antidromic AVRT), or may conduct in the other direction, that is, down the AV node and retrogradely up the bundle of Kent (orthodromic AVRT), to produce a self-perpetuating circus pathway and tachycardia (Figure 5.15). The sensation of palpitations is frightening, and the truncated diastolic filling interval reduces the cardiac output, leading to light-headedness. Conduction down the bundle of Kent is sometimes observed on the normal sinus rhythm ECG, manifesting as a short PR interval with a A (delta) wave as ventricular excitation occurs more rapidly. If a patient with an accessory pathway develop AF, there is a small risk that this will be conducted via the bundle of Kent down to the ventricles and initiate VF and sudden cardiac death. The risk of this is around 1:1000 per year, although it also depends on how well the accessory pathway conducts. Treatment is with pharmacological agents that block the pathway rather than the AV node (such as flecainide or sotalol) or by the destruction of the bundle of Kent via a percutaneous ablation procedure.
Simple electrocardiography algorithm for localizing accessory pathway in patients with Wolff–Parkinson–White syndrome
Published in Acta Cardiologica, 2022
Sunu Budhi Raharjo, Ardhestiro Hanindyo Putro, Anwar Santoso, Dicky Armein Hanafy, Dony Yugo Hermanto, Sarah Humaira, Yoga Yuniadi
Outcome analysis was done by comparing the location of the accessory pathway predicted by 12-lead surface ECG using a simple algorithm and ablation mapping. The representative 12 lead ECG from the patient with left free wall AP (a), septal AP (b), and right free wall AP was shown in Figure 2. The performance of the algorithm in predicting the left free wall pathway, the septal pathway, and the right free wall pathway were shown in Table 2. This algorithm has a sensitivity of 45%, specificity of 96%, PPV of 90%, NPV 70%, and accuracy of 74% for predicting the left free wall (LFW) pathway. Furthermore, it has a sensitivity of 80%, specificity of 69%, PPV of 55%, NPV of 88%, and accuracy of 73% for predicting the septal pathway. Lastly, this algorithm has a sensitivity of 92%, specificity of 86%, PPV of 69%, NPV of 97%, and accuracy of 87% for predicting the right free wall (RFW) pathway.
Wolff Parkinson White and recreational (meth)amphetamine use: a potentially lethal combination
Published in Acta Clinica Belgica, 2021
B. Aspeslagh, P. Calle, J. De Pooter
After resuscitation, he was transferred to a nearby hospital. His ECG showed pre-excitation, compatible with his medical history of WPW (Figure 1). Toxicology (sampled about 2 h after the collapse) was positive for 3,4-methylenedioxyamphetamine (MDA): 10 ng/mL in plasma and 231 ng/mL in urine. Analysis of a similar pill as the one ingested by the patient (handed over by his friends) revealed a content of 45 mg MDA and 15 mg MDMA. After post-resuscitation care, he woke up and was extubated two days later. He underwent electrophysiological testing 3 days later. The electrophysiological study confirmed the presence of a left lateral accessory pathway. Upon the start of atrial pacing, atrial fibrillation (AF) was induced with fast conduction over the accessory pathway resulting in hemodynamically collapse. The shortest pre-excited RR-interval during AF measured 190 ms. He underwent subsequently successful ablation of a left lateral accessory bundle of Kent (Figure 2).
Speckle-tracking imaging for pre-excitation cardiomyopathy
Published in Acta Cardiologica, 2021
Shuai Zhang, Xinjian He, Gaoyang Li, Di Fan
An 8-year-old girl presented to our hospital with chest tightness, fatigue, and discomfort after exercise. A radiograph indicated a large heart shadow. Overt ventricular pre-excitation was noted on the 12-lead electrocardiography (Figure A). Echocardiography demonstrated a 52 mm left ventricular end diastolic diameter (LVEDD) and 31% left ventricular ejection fraction (LVEF). The basal segments of the interventricular septum turned thin and moved similar to an aneurysm. Left ventricular longitudinal and radial strain from the apical four-chamber and parasternal short-axis view revealed interventricular septal paradoxical motion (Figure B and C, arrow, reversed strain). The standard deviation of the time to the peak systolic strain (Ts-SD) over 18 longitudinal segments was 124 ms. Electrophysiological examination of the heart demonstrated the presence of a right pathway, and this pathway was successfully ablated using radiofrequency ablation. The left ventricular dysfunction and dyssynchrony reversed following catheter ablation of the accessory pathway 7 months later (LVEDD = 45mm, LVEF = 45%, and Ts-SD = 34ms) (Figure D and E). However, we needed to exclude the possibility of tachycardiomyopathy before the diagnosis of preexcitation cardiomyopathy was established. In this case, our patient never experienced an incessant and prolonged tachyarrhythmia. Hence, the diagnosis of pre-excitation cardiomyopathy was reasonable, and the pathogenesis of left ventricular dysfunction could be associated with ventricular dyssynchrony caused by ventricular pre-excitation.