ECG feature of acute cor pulmonale (e.g. Pulmonary embolism)

Ans. d (All of the above three) (Ref. H-17th/139l).Harrison-17th/p. 1391:ECG in Acute cor pulmonale due to pulmonary embolism# Normal ECG may be seen# Sinus tachycardia (most common arrhythmia)# Tachyarrhythmias, such as atrial fibrillation or flutter# The QRS axis may shift to the right, sometimes in concert with the so-called S1Q3T3 pattern (prominence of the S wave in lead I, Q wave in lead III, with T-wave inversion in lead III).# Acute right ventricular dilation may also be associated with slow R-wave progression and T-wave inversions in V1 to V4 simulating acute anterior infarction.# A right ventricular conduction disturbance may appear.Chronic cor pulmonale due to obstructive lung disease# Usually does not produce the classic ECG patterns of right ventricular hypertrophy.# Instead of tall right precordial R waves, chronic lung disease more typically is associated with small R waves in right-to-midprecordial leads (slow R-wave progression) due in part to downward displacement of the diaphragm and the heart.# Low-voltage complexes are commonly present, owing to hyperaeration of the lungs.Characteristic ECG features of few conditionsDigitalis intoxication# "Hockey stick" pattern # short QT interval # Scooping of ST-T wave complexSAH# CVA T wave pattern.Hypercalcemia# Short ST segment and reduced QT intervalHypocalcemia# Prolonged QT intervalTCA overdose# QRS and QT prolongation with sinus tachycardiaHypothermia# Convex jump at J point (Osborn wave)Hypokalemia/ Quinidine excess# Prolonged QT, prominent U waves and susceptible to torsadesHyperkalemia# Tenting of T-waves (r) wide QRS interval and reduced P wave amplitude, prolonged PR interval (r) Sine-wave pattern (r) asystole.Acute cor pumonale# S1Q3T3 pattern# Slow "r" wave progression in leads V1 to V4# Atrial fibrillationWPW# Wide QRS complex# RR interval is Relatively short# Wave delta (Slurring of the initial part of the QRS).ALSO KNOW# P wave = represents atrial depolarization# QRS complex = represents ventricular depolarization# ST-T-U complex (ST segment, T wave, and U wave) = represents ventricular repolarization.# J point = is the junction between the end of the QRS complex and the beginning of the ST segment.# There are four major ECG intervals: R-R, PR, QRS, and QT.- The heart rate (beats per minute) can be readily computed from the interbeat (R-R) interval by dividing the number of large (0.20 s) time units between consecutive R waves into 300 or the number of small (0.04 s) units into 1500.- The PR interval measures the time (normally 120-200 ms) between atrial and ventricular depolarization, which includes the physiologic delay imposed by stimulation of cells in the AV junction area.- The QRS interval (normally 100-110 ms or less) reflects the duration of ventricular depolarization.- The QT interval includes both ventricular depolarization and repolarization times and varies inversely with the heart rate. A rate-related ("corrected") QT interval, QTc, can be calculated and normally is 0.44 s. (Some references give QTc upper normal limits as 0.43 s in men and 0.45 s in women.)