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Neurologic Diagnosis
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Antidromic conduction can be assessed in accessible sensory or mixed sensorimotor nerves by electrically stimulating the sensory nerve proximally (e.g. the median or ulnar nerve at the wrist) and recording the resulting sensory nerve action potential (SNAP) distally (e.g. from surface ring electrodes placed around the index or little fingers, respectively) (see Figure 1.44b). Alternatively, orthodromic conduction can be assessed by stimulating the distal sensory fibers (e.g. median nerve with electrodes on the palm or ring electrodes on the index finger) and recording the SNAP with electrodes over the nerve more proximally (e.g. median nerve at the wrist; Figure 1.46).
Arrhythmias in Pregnancy
Published in Afshan B. Hameed, Diana S. Wolfe, Cardio-Obstetrics, 2020
Dana Senderoff Berger, Lee Brian Padove
The reentrant arrhythmia is usually orthodromic, i.e., narrow QRS complex SVT. Impulse travels from atrium to ventricle and then retrograde through the accessory pathway. Usual agents used to treat SVT can safely be used in pregnancy [8].
Supraventricular rhythms
Published in Andrew R Houghton, Making Sense of the ECG, 2019
In the vast majority (95%) of episodes of AVRT seen in patients with WPW syndrome, the re-entry circuit travels down the AV node and back up the accessory pathway (Figure 7.16). This is known as an orthodromic AVRT and is usually triggered by an atrial ectopic beat which occurs while the accessory pathway is refractory to conduction – this ectopic is therefore conducted down the AV node but not down the accessory pathway. However, by the time that the impulse subsequently reaches the ventricular side of the accessory pathway, the pathway is no longer refractory and can conduct the impulse retrogradely back up to the atria, thus setting up a re-entry circuit. The ECG during orthodromic AVRT (Figure 7.17) shows: Regular QRS complexesNarrow QRS complexesHeart rate 130–220/min
Atypical tachycardia mimicking typical reentry: what is the mechanism?
Published in Acta Cardiologica, 2022
Hussam Ali, Guido De Ambroggi, Pierpaolo Lupo, Sara Foresti, Carmine De Lucia, Riccardo Cappato
While 2:1 AV block during the ongoing tachycardia ruled out orthodromic AV re-entry via an accessory AV pathway, the reproducible paradoxical delay in atrial activation by ventricular extrastimuli made atrial tachycardia unlikely as a mechanism. Based on these features, adenosine sensibility, and the presence of dual nodal physiology the most likely mechanism was atypical (fast-slow) AV nodal re-entrant tachycardia (AVNRT). Ventricular entrainment is another useful pacing manoeuvre to differentiate between AVNRT and orthodromic AV re-entry using a septal accessory pathway. During this manoeuvre, longer postpacing intervals (>115 ms compared to tachycardia cycle length), and stimulus-atrium intervals (>85 ms compared to tachycardia VA interval) favour the diagnosis of AVNRT. However, para-Hisian pacing manoeuvre performed in our patient at fast rates (280 ms) during the basal study, showed a nodal response with the same retrograde atrial activation supporting the diagnosis of AVNRT (Figure 1C).
Real world data on non-complex catheter ablations performed on zero fluoroscopy in a secondary centre in the south of Belgium
Published in Acta Cardiologica, 2021
Lucio Capulzini, Christophe de Terwangne, Gianbattista Chierchia, Carlo de Asmundis, Gaetano Paparella, Antonio Sorgente
Table 1 shows their demographic and clinical characteristics. Table 2 shows the procedural characteristics. Right atrial flutters and typical atrioventricular nodal re-entry tachycardia (AVNRT) were the most common arrhythmia treated, corresponding together to the 81% of the total. Two patients demonstrated to be affected by orthodromic AVRT through a manifest right mid-septal and a concealed left lateral atrio-ventricular accessory pathway, respectively. Three patients underwent uneventfully catheter ablation of a PVC originating respectively from the anteroseptal free wall (2) and postero-septal aspect of the right ventricular outflow tract (RVOT). Right femoral access was obtained in 86% of cases with left femoral access used in the remaining when right femoral access was not successful after the third attempt. Coronary sinus cannulation was efficacious within 10 min in 76% of cases.
Management of Wolff-Parkinson-White syndrome in a patient with peripartum cardiomyopathy
Published in Journal of Community Hospital Internal Medicine Perspectives, 2021
Snigdha Bendaram, Sherif Elkattawy, Muhammad Atif Masood Noori, Hardik Fichadiya, Sarah Ayad, Parminder Kaur, Raja Pullatt, Fayez Shamoon
In ED, the patient was found to have a BP of 76/50. EKG (EKG a) showed Narrow complex tachycardia with a nonspecific intraventricular block and a heart rate of 190 beats per minutelikely mechanism being orthodromic AVRT given presence of delta wave in prior resting EKG. Also, a QTc of 533 milliseconds was noted. Serum magnesium was 1.6 mg/dl, which was repleted. She was treated with two doses of 100 mg intravenous procainamide, which reverted the cardiac rhythm to sinus rhythm and raised the patients blood pressure to 110/70 mmHg. A white blood cell count of 12,4004/mm3 (Normal range 4,000–10,000) was noted. Brain natriuretic peptide levels were 916 pg/ml (Normal <100). Chest X-ray showed findings suggestive of a small left pleural effusion; CT angiography was negative for Pulmonary embolism but did show findings concerning left lower lobe bronchopneumonia with trace pericardial and bilateral pleural effusions. The patient was given ceftriaxone and doxycycline, was continued on procainamide infusion and admitted to the Intensive care unit for further management.