The Netter Collection of Medical Illustrations, Volume 8: Cardiovascular System (2nd Edition)

LEFT ATRIAL expansion not like definitely the right atrium, left atrial growth factors the ECG photo of “P mitrale. ” This frequently is attributable to mitral stenosis or regurgitation incident to rheumatic middle sickness. The P waves are notched and extensive in lead II, with a bent to left axis deviation, yet ordinarily are basic in peak. there's expansion of the left atrium, in comparison with the ideal; as a result the electrical forces are directed towards the left axilla. traditionally, the P waves in lead II are broad (≥0. 12 second). The loop of the P wave is strangely huge and exhibits a left axis deviation. huge, notched P waves are also visible in lead V6. With left atrial growth, the past due P vectors are huge in comparison to the early vectors (see Plate 2-20). expansion OF either ATRIA whilst either correct and left atria are enlarged, the P waves are tall—more than 2. 5 mm in lead II—and vast (≥0. 12 THE NETTER selection of scientific ILLUSTRATIONS aVF aVF 12 1 V2 second). Notching is current. This situation happens whilst mitral valve sickness prevails within the presence of an interatrial septal illness or while a number of valvular defects are current. The atrial T waves or the repolarization waves of the atria are generally small, usually being undetectable or misplaced within the QRS complexes. often, the T wave is discordant with the P wave, in confident P wave is generally by way of a truly small, 2 V6 V1 adverse T wave. normally, the world lower than the atrial T wave is a bit of smaller than the world less than the P wave. With growth of the P waves, in both “P mitrale” or “P pulmonale,” the atrial T waves amplify in percentage to the elevated measurement of the P waves, with resultant melancholy of the P-R segments. huge atrial T waves usually name realization to atrial abnormalities and are important diagnostically. 39  Plate 2-21  Cardiovascular process correct ventricular hypertrophy Ventricular Hypertrophy Septal depolarization a variety of phrases were used to explain the ECG photo of ventricular hypertrophy, together with ventricular preponderance, pressure, systolic or diastolic overload, and expansion. a few of these describe a useful nation of overwork of 1 ventricle as opposed to the opposite, or discuss with an anatomic situation with elevated muscle of 1 ventricle in comparison to the opposite. Ventricular preponderance is an all-inclusive time period that largely contains so much stipulations, and expansion covers either hypertrophy and dilatation. Apical depolarization T V6 correct VENTRICULAR HYPERTROPHY The QRS forces are directed to the perfect a result of thick correct ventricle, which distorts the horizontal loop to the suitable and ahead, and is linked to tall R waves relative to basic in leads V1 and V2 and deep S waves in leads V4 and V5 (see Plate 2-21). The R/S amplitude ratio in lead V1 is irregular, indicating a tall R wave with appreciate to the intensity of the S wave. as a rule, this ratio will be lower than 1. often, the S-T segments and T waves are contrary in course to that element of the QRS advanced of maximum region (usually the R wave), and likewise the T loop is contrary to the QRS loop.