JORGENSEN J1010, Руководство пользователя

Страница: 29 / 32

34
Effect of Selected Diseases on the Electrocardiogram
Hyperkalemia
Hyperkalemia is a common clinical problem in cats with urinary tract obstruction. Addison’s disease
is a common cause of hyperkalemia in the dog.
ECG Changes:
K+>5.5 mEq/l: T waves larger and peaked.
K+>6.5 mEq/l: R wave decreased, QRS prolonged, P-R interval prolonged.
K+>7.0 mEq/l: P wave amplitude decreased, P wave duration increased, QRS longer, P-R interval
longer, Q-T interval prolonged.
K+>8.5 mEq/l: P wave disappearance, atrial standstill, sinoventricular rhythm.
K+>10.0 mEq/l: Ventricular fibrillation or ventricular asystole.
Figure 4-30 (A) Hyperkalemia in a dog presenting with hypovolemic shock due to addisonian crisis.
P waves are absent and T waves are tall and peaked. Serum potassium was 8.4 mEq?L. (B) After
institution of therapy, P waves are present and the QRS-T complex is of smaller amplitude. Serum
potassium was 4.8 mEq/L. (Tilley LP: Essentials of Canine and Feline Electrocardiography, 2nd Ed.
Lea & Febiger, Philadelphia, 1985.)
Pericardial Effusion
ECG: Decreased QRS amplitude, S-T segment elevation in lead II and P-R segment depression in
lead II.
Figure 4-31 Electrical alternans in a dog with pericardial effusion. Every other R wave alternates in
amplitude.
26