诊断学课件器械检查部分房室大和心肌梗死.ppt

Part III  Atrial Enlargement and Ventricular Hypertrophy 薛小临 (1) Left Atrial Enlargement Lead II Duration of P wave ≥0.12 sec. ; P wave become bifid (P mitrale); The distance of two peak ≥ 0.04sec. Lead V1 P wave become biphasic; Ptfv1 ? - 0.04 mm·sec Right Atrial Enlargement Lead II P wave is peaked (P pulmonale); Amplitude of P wave ≥0.25 mV in limb leads. Biatrial Enlargement Lead II P wave duration and amplitude both increased. Left Ventricular Hypertrophy A. Increased voltage SV1 + R V5 3.5mV (female), 4.0mV (male); Rv5 or Rv6 2.5 mV; ? RI 1.5mV; ? RaVL 1.2mV; ? RaVF 2.0 mV; ? RI + SIII 2.5 mV; B. Left axis deviation C. ST depression and T inversion in V5-6. Right Ventricular Hypertrophy A. Increased voltage (adults over 30) R/S ratio in V1 1.0; R/S ratio in V5 or V6 ≤ 1.0; R/q or R/S ratio in aVR≥1; R V1+ S V5 1.05mV (severe1.2mV); RaVR0.5mV; B. Right axis deviation ≥ +900 (severe +1100). C. ST depression and T inversion V1-2. Biventricular Hypertrophy A.?? Normal ECG. B.?? One ventricular hypertrophy. C.?? Biventricular Hypertrophy. Part VI Myocardial Ischemia and Myocardial infarction ECG of myocardial ischemia shows: ST segment depression; ST segment elevation( coronary spasm); Inverted, diphasic, low T wave. Myocardial infarction (1) Basic changes “Hyperacute” T Waves. Tall peaked T waves, often appear as the earliest ECG sign of acute MI. ST Elevations. The ST segment elevated in one or more leads and may be straightened and fuse with the T wave (mono-phasic curve) Pathologic Q Waves. the sudden developed Q wave may indicate an acute MI. T Wave Changes. The elevated ST segments return to the baseline, and deep symmetrical T waves appear in these leads. Tall, symmetrical, upright T waves will appear in reciprocal leads at the same time. (2) Progressive ECG changes (3) Localization of the ECG patterns Leads with Abnormal