KIN 494: normal findings

Normal findings of a Pwave?

Duration: 0.10 secAmplitude: 0.5 and 2.5 mmUpright: I, II, avF, V4, V5, V6 Inverted: aVR Variable: III, avL, V1, V2, V3

Abnormal findings of a Pwave?

M shaped or notched P Wave M-Mitral: Left atrial enlargement Peaked P Wave (over .11 sec) Right atrial enlargement atrial dilatation P Waves absent Sinoatrial node block AV Nodal rhythm

Normal PR Interval?

Duration: 0.12 to 0.20 secProlonged PR interval (> .20) AV Node Block Shortened PR interval (< .12, accelerated) Wolf-Parkinson-White Syndrome (WPW syndrome) PR segment: normally isoelectric (not measured)

Normal Q wave?

Duration: 0.04 sec (1 small boxes) Amplitude: < 25% of amplitude of R wave in that lead Always the first negative deflection below baseline Variable: III, aVRmay not always have one

normal RS Wave?

Negative waveform (below baseline) following R Depolarization of right and left ventricle

normal QRS complex?

Duration: Limb leads (I, II, III): ? 0.10 Prolonged QRS complex (> 0.12) High QRS amplitude Evaluate for Left Ventricular Hypertrophy (LVH) Upright I, aVL, V5, V6 and II, III, and aVF

normal J point?

Point at the end of the QRS complex and the beginning of the ST segmentshould be aligned with beginning of Q wave to be normal

normal ST segment?

a little down or up slope is fineST segment is isoelectricEarly part of repolarization of the ventricles PR segment is used as baseline for identification of deviation from baseline Measure 2 small box (0.08 sec) from J point Elevation or Depression with 2 small box above or below in multiple leads

Normal T wave?

Smooth and asymetrical Amplitude : <5 mm Upright: I, II, V3, V4, V5, V6 Tall T Waves: Myocardial infarction, Myocardial ischemia, Cerebrovascular accidentgoes hand in hand with the QRS complex

normal QT interval?

Normal QT decreases with increasing heart rate Calculation of QTc or corrected QT (Bazett's Formula) QTc = QT/(sqrt RR Interval) QTc is normally <0.44a long interval could be for an athlete or someone with hypertension

What is the large box method?

its is a close estimatecount the number of large boxes (5mm) between beatsdivide by 300 (=1 minute)

small box method?

count number of small boxes (1mm) between beatsdivide by 1500 ( =1minute)