Electrocardiogram Interpretation for Electrode Placement and Cardiac

Question: Discuss about theElectrocardiogram Interpretation for Electrode Placement and Cardiac. Answer: Analysis There is sinus rhythm with a rate of 75bpm (normal rhythm is 60-100 bpm). The cardiac axis is deviated to the left. The electrical depolarization wave is moving toward the left shown by the positive R wave in lead I but negative in lead II and III. The PR interval is normal at 120 ms (normal PR interval 120-200 ms) with normal P waves as the P wave corresponds to one QRScomplex. This shows each P wave is conducted leading to ventricular depolarization shown by a QRS complex. The QRS complex pattern shows right bundle branch block as shown by the rSR pattern in right ventricular leads VI and VII. In a right bundle block no conduction occurs in the right bundle branch but the septum is depolarized from right to left as usual causing an R wave in VI. Then excitation spreads to the left ventricle causing an S wave in VI. Due to faulty conduction the right ventricle depolarizes after the left causing a second R wave on VI. This explains the RSR pattern on VI and VII (Hampton, J. 2013). A right bundle block is however associated with a normal cardiac axis hence due to the left axis deviation a bifascicular block is suspected. ECG 2 (ECGimagejaiden2) Sinus rhythm with 100 beats per minute. Cardiac axis normal. P wave present before each QRS complex. Prolonged PR interval at 160ms. QRS complex present each preceded by a P wave. QRS interval normal at 120ms. M pattern present with deep S waves deep at lead VI, V2. S wave absent on lead V6 ST segment elevated best seen at lead VI and V2. T wave inverted at lead I, II, VI, V2 Interpretation Left Bundle Branch Block. Analysis There is sinus rhythm with a rate of 100bpm (normal rhythm is 60-100 bpm). The cardiac axis is normal. The electrical depolarization wave is moving toward lead I shown by positive R wave in lead I, lead II and III. The PR interval is normal at 160 ms (normal PR interval 120-200 ms) with normal P waves as the P wave corresponds to one QRS complex. This shows each P wave is conducted leading to ventricular depolarization shown by a QRS complex. The QRS complex pattern shows left bundle branch block as shown by the M pattern in lead opposite to right ventricular leads VI and VII, and in left ventricular leads V6 and deep S waves in VI and VII. In left bundle block no conduction occurs down the left branch so the septum is depolarized from right to left causing a small Q wave in lead V1 and an R wave in V6. The right ventricle is depolarized before the left. Despite the small muscle mass there is an R wave in VI and an S wave in V6 appearing as a notch (M pattern). Left bundle block is a lso associated with T wave inversion as seen in lead VI and VII (Hampton, J. 2013). The impression is a left bundle branch block. ECG 3 (ECGanalysis1brownyn) Sinus rhythm with sinus bradycardia 33beats per minute. Cardiac axis is normal. P wave present. 2P wave per QRS. PR interval constant, prolonged at 400ms. QRS complex is normal QRS interval at 100ms. PR interval is prolonged at 400ms The ST interval is normal. There are large T waves in most leads. Interpretation Second degree heart block, Mobitz type 2 Analysis There is a sinus rhythm with a sinus bradycardia of 33 beats per minute. There is a normal cardiac normal. The electrical conduction starts with a P wave, two P waves per QRS. The PR interval is prolonged at 400ms and it remains constant pointing to a morbitz type II heart block. The QRS complex is normal with a normal interval. ST is normal with large T waves (MacFariane et al., 2010) ECG 4 (ECG2analysisbrownyn) Sinus rhythm with sinus bradycardia 42 beats per minute. Cardiac axis is normal. P waves present, although not all translates to a QRS. PR interval not constant, its lengthens progressively, conducts then lengthens. This cycle repeats itself. QRS complex is normal. QRS interval normal at 120ms The ST interval normal. Interpretation Second degree heart block Wenckebach phenomena. Analysis There is a sinus rhythm with a sinus bradycardia, 42 beats per minute. Every cycle starts with a P wave, a QRS complex follows the P waves although not all P waves translates to a QRS. The PR is not constant, it lengthens progressively, then conducts and lengthens again (MacFariane et al., 2010) References Davidsons, J., (2014). Cardiovascular system. Principles and practices of medicine. Pg. 67-98, 22nd edition. MacFariane et al., (2010). Comprehensive electrocardiology. Springer. Hannibal, B., (2014). Electrode placement and Cardiac monitoring. Advanced critical care AACN, 25, 2, 188-192 Hampton, J. (2013). ECG made easy.6 ed. pg 20-40.