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Case studies: urgent decisions in interventional radiology
Published in William H. Bush, Karl N. Krecke, Bernard F. King, Michael A. Bettmann, Radiology Life Support (Rad-LS), 2017
Discussion It is very common for ectopy to occur during pulmonary angiography as the right ventricle is traversed with the guidewire and catheter, due to the irritability of this chamber. This is particularly troublesome in certain patients, such as those who are recently post myocardial infarction (MI), have had recent cardiac surgery, have underlying arrhythmias or have a left bundle branch block. These arrhythmias generally consist of runs of premature ventricular contractions (PVCs). They almost always stop when the catheter and guidewire are removed from the right ventricle, or when the right ventricle is traversed and the catheter and guidewire lie in the pulmonary artery. Great care must be taken in all patients to ensure that the catheter is not positioned so as to allow the arrhythmias to persist. Some angiographers are careful to have a transcutaneous pacemaker or a transvenous pacing wire available in the case of patients with a history of arrhythmias, particularly those with left bundle branch block. No other specific precautions are necessary.
Solving Inverse Problem in Magnetocardiography by Pattern Search Method
Published in IETE Journal of Research, 2021
Pragyna Parimita Swain, S. Sengottuvel, Rajesh Patel, Awadhesh Mani, Raja J. Selvaraj, Santhosh Satheesh
Right Bundle Branch Block (RBBB) is a conduction anomaly that occurs due to the blockage of the right bundle branch of the electrical conduction system of the heart. As a result of this block, the right ventricle is not directly activated by the usual route of conduction and passively gets activated through myocardial muscle (causing delayed conduction) after the depolarization of the left ventricle. In Figure 8(a), the averaged cardiac traces collected from all thirty-six locations over the thorax of a subject with RBBB are superposed and shown as the butterfly plot. As opposed to the narrow QRS peak signifying fast activation of both ventricles in a normal subject, QRS is found to be relatively broad (exceeding 150 ms) in subjects with RBBB. We analyzed the cardiac source around the S peak time instant to highlight this characteristic anomaly associated with bundle branch blocks. By dividing the R-S interval (from the end of the R peak to the end of S peak) into 8 equal intervals of 12 ms duration in each slot, the cardiac sources are estimated and analyzed as shown in Figure 8(b).