Comparison of the influence of acute transmural and nontransmural myocardial infarction on ventricular function

In order to assess the relative impact on left and right ventricular function of nontransmural and transmural acute myocardial infarction (AMI), we performed radionuclide ventriculography in 86 patients (54 men and 32 women) within 16 hours after a first infarct. Nontransmural infarction was present in 19 patients (11 anterior and 8 inferior). Transmural infarction was found in 67 patients (30 anterior and 37 inferior). Left ventricular ejection fractions were higher (0.57 +/- .014 vs 0.46 +/- 0.14, p less than 0.005) and left ventricular end-systolic volume lower (29 +/- 11 vs 42 +/- 20 ml/m2, p = 0.013) in patients with nontransmural infarction compared to those with transmural infarction. Right ventricular ejection fraction also may have been different in the two groups (0.63 +/- 0.15 vs 0.55 +/- 0.13, p = 0.057). In patients with inferior infarction, left and right ventricular ejection fractions were similar in patients with nontransmural and transmural infarction (0.60 +/- 0.09 vs 0.55 +/- 0.10, p = 0.119 and 0.58 +/- 0.14 vs 0.51 +/- 12, p = 0.226). On the other hand, patients with anterior transmural infarction had lower left ventricular ejection fractions (0.36 +/- 0.12 vs 0.54 +/- 0.17, p = 0.003) but similar right ventricular ejection fractions (0.60 +/- 0.13 vs 0.66 +/- 0.14, p = 0.14) compared to those with nontransmural anterior infarction. In 29 additional patients with a history of previous infarction, no differences in any of the parameters studied were found between those with transmural and those with nontransmural infarcts.(ABSTRACT TRUNCATED AT 250 WORDS

Contrast injection bradycardia during coronary angiography: effects in the denervated human heart.

To assess the contribution of cardiac innervation toward understanding the mechanisms of bradycardia during contrast coronary angiography, heart rate (HR) responses in eight patients after heart transplantation were compared with 10 normal patients (control), 10 patients with coronary artery disease (CAD) and normal ventricular function, and 10 patients with congestive cardiomyopathy and normal coronary arteries. The longest P-P interval was measured beat to beat before (HR 1) and after (HR 2) coronary angiography. The coronary vessel perfusing the sinus node did not influence HR 2 responses within each group. HR 1 was significantly different from HR 2 (p less than 0.05) in the control and CAD groups but was not different in the transplant and cardiomyopathy groups. Compared with the control group, the percent decrease in HR was significantly less in transplant patients than in patients with cardiomyopathy. Thus contrast injection bradycardia is absent in denervated patients after heart transplant, and this response is markedly blunted in cardiomyopathy patients who are known to have diminished vasodepressor reflexes. These findings suggest that the bradycardia response is probably a neurally mediated phenomenon