Postsystolic shortening of ischemic myocardium: a mechanism of abnormal intraventricular filling

• Published in: American journal of physiology. Heart and circulatory physiology 2003-06, Vol.284 (6), p.H2343-H2350
• Main Authors: Urheim, Stig, Edvardsen, Thor, Steine, Kjetil, Skulstad, Helge, Lyseggen, Erik, Rodevand, Olaf, Smiseth, Otto A
• Format: Article
• Language: English
• Subjects: Animals; Atrial Function, Left - physiology; Blood Pressure - physiology; Dogs; Echocardiography, Doppler, Color; Electrocardiography; Female; Heart Rate - physiology; Heart Ventricles - physiopathology; Male; Myocardial Contraction - physiology; Myocardial Ischemia - physiopathology; Systole - physiology; Ventricular Function, Left - physiology
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00320.2002

Institute for Surgical Research and Department of Cardiology, Rikshospitalet, Oslo, N-0027 Norway Acute myocardial ischemia has been associated with abnormal filling patterns in the left ventricular (LV) apex. We hypothesized that this may in part be due to postsystolic shortening of ischemic apical segments, which leads to reversal of early diastolic apical flow. Fourteen open-chest anesthetized dogs were instrumented with micromanometers in the LV apex and left atrium and myocardial sonomicrometers in the anterior apical LV wall. Intraventricular filling by color Doppler and wall motion by strain Doppler echocardiography (SDE) were assessed from an apical view. Measurements were taken before and after 5 min of left anterior descending coronary artery (LAD) occlusion. In four dogs, we measured the pressure difference between the LV apex and outflow tract. At baseline, peak early diastolic flow velocities in the distal one-third of the LV were directed toward apex (9.2 ± 1.6 cm/s). After LAD occlusion, the velocities reversed ( 2.3 ± 0.4 cm/s, P