Related Experiment Videos
Quantitative analysis of myocardial infarct structure in patients with ventricular tachycardia
Insights
Patients with ventricular tachycardia experience larger, more solid myocardial infarctions with distinct patterns of spared subendocardium compared to controls. This finding aids in understanding the anatomical basis of ventricular tachycardia.
Area of Science:
- Cardiovascular Pathology
- Cardiac Electrophysiology
Background:
- Ventricular tachycardia (VT) is a significant complication of myocardial infarction (MI).
- Understanding the distinct cardiac structural changes associated with VT post-MI is crucial for improving patient outcomes.
Purpose of the Study:
- To quantitatively compare the characteristics of myocardial infarction in deceased patients with and without a history of ventricular tachycardia.
- To elucidate the specific histological differences in infarcts and spared subendocardium in VT patients.
Main Methods:
- Quantitative analysis of hearts from 22 deceased patients with VT and 21 controls.
- Histological examination of myocardial infarcts and subendocardial tissue.
- Categorization of VT patients into subacute (<=10 weeks post-MI) and chronic (>10 weeks post-MI) subgroups.
Main Results:
- Hearts from the VT group were heavier and more dilated than controls.
- VT patients exhibited larger, more solid infarcts and a greater area of "ribbon type" spared subendocardium.
- Subacute VT patients had more solid infarcts and greater "ribbon type" spared subendocardium than chronic VT patients.
Conclusions:
- Significant differences exist in myocardial infarction morphology between patients with and without ventricular tachycardia.
- The specific patterns of infarcts and spared subendocardium in VT patients provide insights into the anatomical substrate for VT.
- Findings can inform the evaluation of animal models and intraoperative mapping for VT.
Abstract:
To study whether myocardial infarction differs in patients with and without ventricular tachycardia, the hearts of 22 deceased patients with ventricular tachycardia and 21 deceased control patients were analyzed quantitatively. The hearts from the ventricular tachycardia group were heavier and more dilated than those from the control group. Histologic analysis of a representative cross section from each heart showed that the ventricular tachycardia group had larger, more solid infarcts than did the control group. The ventricular tachycardia group also had a greater area of spared subendocardium, more hydropic change of the spared subendocardium, and more "ribbon type" spared subendocardium, which was defined as spared subendocardium of uniform contour 1 mm thick or less. The ventricular tachycardia group was divided into a subacute subgroup (n = 14, dying less than or equal to 10 weeks after infarction) and a chronic subgroup (n = 8, dying greater than 10 weeks after infarction). The infarcts of the subacute ventricular tachycardia group were more solid and had a greater amount of ribbon type spared subendocardium than those of the chronic ventricular tachycardia group. This information can serve as a baseline for the evaluation of animal preparations of tachycardia and, when combined with knowledge of the location of the arrhythmogenic region furnished by intraoperative mapping, should lead to better understanding of the anatomic substrate for ventricular tachycardia.