tailieunhanh - Ebook ECG from basics to essentials - Step by step: Part 2

(BQ) Part 2 book "ECG from basics to essentials - Step by step" presents the following contents: Acute pericarditis, the ECG in extracardiac disease, sinus node dysfunction, premature ventricular complexes (PVC), atrioventricular block, atrial rhythm disorders, ventricular fibrillation and ventricular flutter,. and other contents. | CHAPTER 9 ACUTE PERICARDITIS 187 Clinical stages Other conditions with similar features Differential diagnosis Early repolarization ECG from Basics to Essentials Step by Step. First Edition. Roland X. Stroobandt S. Serge Barold and Alfons F. Sinnaeve. Published 2016 2016 by John Wiley Sons Ltd. Companion Website go stroobandt ecg 188 ACUTE PERICARDITIS 1 ECG changes in acute pericarditis mainly indicate inflammation of the epicardium the layer directly surrounding the heart . The ECG is useful in the diagnosis of acute pericarditis with abnormalities found in approximately 90 of cases. Not all cases of pericarditis include each of the four stages shown below. In fact all four stages are present in only 50 of patients or less. Stage I The most sensitive ECG change characteristic of acute pericarditis is ST segment elevation which reflects the abnormal repolarization that develops secondary to pericardial inflammation. The ST elevation occurs during the first few days of pericardial inflammation and is mainly characterized by diffuse upward concavity saddle-shaped . ST segment elevation is usually less than 5 mm with concordance of the T wave. ST elevation involves the limb leads and precordial leads with reciprocal ST segment depression only in aVR and V1. This limited change in aVR and V1 represents a lack of substantial reciprocal changes corresponding to the extensive ST elevation. PR segment depression that may be subtle 1 mm or so may occur in all the leads except aVR and V1 where the PR segment may be elevated. The PR changes are thought to be due to atrial wall injury. Thus the PR and ST changes are opposite in direction. The PR changes are very specific and may be earliest manifestation of pericarditis. The ECG may show low voltage . decreased amplitude of the QRS complexes and there are no Q waves. This stage may last up to two weeks. Stage II Normalization of ST and PR deviations T wave flattening. This stage lasts from days to several .