Search

Patients complaining of chest pain after a traumatic event represent a diagnostic challenge for the cardiologist. These patients can definitely escape from common diagnostic tests (particularly ECG and markers of myocardial lysis) that may guide the cardiologist, mostly because symptoms are attributed to the trauma itself. On the other hand, if blunt cardiac injury is suspected (involving coronary arteries, aorta, pulmonary trunk, pericardium, myocardium or valves), the selection of the most appropriate diagnostic and therapeutic tools (i.e. antithrombotic therapy) should also consider trauma involvement of other organs. We here describe two emblematic cases as examples of the challenges that diagnosis and treatment of cardiac injury can bring.

Although in experimental models of coronary occlusion diltiazem administration has been shown to reduce the degree of stunning and of reperfusion injury, the majority of clinical trials has failed to demonstrate significant benefits. The aim of this study was to evaluate the effect of diltiazem, administered before coronary reperfusion, on infarct size, residual myocardial viability and recovery of left ventricular function.We studied 90 patients admitted within 3 hours of the onset of symptoms of acute myocardial infarction. They were immediately randomized to either intravenous diltiazem (10 mg bolus + 10 mg/hour for 3 days) (group 1, n = 43) or placebo (group 2, n = 47) and subsequently treated with recombinant tissue-type plasminogen activator. All underwent serial echocardiograms upon admission, 4 days post-admission during low-dose dobutamine stress echo, at discharge and after 6 months. We calculated the dysfunction score (1 = hypokinesia, 2 = akinesia, 3 = dyskinesia) on admission and its percent reduction after dobutamine (viability) and at follow-up (recovery). The 12-lead electrocardiograms were continuously monitored for 3 days and coronary angioplasty was performed whenever the residual stenosis was60%.Upon admission, there were no differences in age, sex, infarct location and size, degree of ST-segment elevation, time from onset of symptoms and dysfunction score. Creatine kinase peaked early in 70% of patients in both groups; the incidences of recurrent ischemia, infarct-related vessel patency and the need for coronary angioplasty were also similar. The creatine kinase peak was significantly higher in group 2 (2931 +/- 2456 vs 1726 +/- 1004 IU/l, p0.05). Conversely, in group 1 the residual viability was significantly higher (51 +/- 23 vs 36 +/- 30% improvement in dysfunction score, p0.05) and the early recovery of regional function was significantly greater (35 +/- 34 vs 18 +/- 22% at discharge, p0.05). On the other hand, the delayed recovery was not significantly different (15 +/- 29 vs 21 +/- 32% from the time of discharge to 6 months of follow-up).Intravenous diltiazem, started before coronary reperfusion, has beneficial effects on the infarct size, residual viability and recovery of regional function. If confirmed by larger trials, these preliminary results suggest the use of diltiazem as adjunctive therapy in patients with acute myocardial infarction and undergoing reperfusion.

Aims We investigated the ability of T-wave pseudonormalization and ST-segment elevation, which are demonstrated in infarct-related leads during submaximal exercise testing, to predict late recovery of contractile function. Methods We studied 88 consecutive patients (73 males, mean age 59+/-8 years) with anterior infarction, persistent T-wave inversion and a documented lesion of the proximal segment of the left anterior descending coronary artery. They all underwent 2D-echocardiography on admission, 4 weeks as well as 6 months after myocardial infarction to evaluate the dysfunction score and the ejection fraction. Submaximal (75% of maximal predicted heart rate) exercise testing was performed in 80 patients 2 weeks after myocardial infarction following discontinuation of treatment. Results During exercise testing, 59 of the 88 patients showing negative T-waves on the resting electrocardiogram exhibited pseudonormalization (group A) in at least three adjacent precordial leads, whilst 29 (group B) did not. Patients of group A more frequently exhibited an early creatine kinase peak (41% vs 24%, P

Background Controversial evidence exists as to whether thrombolytic therapy reduces the incidence of left ventricular thrombus in acute myocardial infarction and, if so, how this relates to successful reperfusion. Methods Four hundred and eighteen consecutive patients underwent echocardiography and coronary angiography within 3 weeks of an acute myocardial infarction. A dyssynergic score was calculated by analysing regional wall motion in 18 left ventricular segments. The infarct-related artery was considered patent if TIMI grade 2 or 3 flow and less than 90% stenosis were present. Retrograde perfusion by Rentrop's grade 2 or 3 collaterals was considered significant. Results Large anterior myocardial infarctions were associated with the highest prevalence (39%) of left ventricular thrombosis. Thrombus was also very frequent if the left anterior descending coronary artery was occluded and no collaterals to the infarct area were seen (75%). Anticoagulant therapy reduced the prevalence of left ventricular thrombus, regardless of whether the infarct-related vessel was patent or not. Conversely, in patients undergoing thrombolysis the incidence of left ventricular thrombosis was lower when the left anterior descending coronary artery was patent, and especially when an early creatine kinase peak, suggestive of reperfusion, was recorded (7%). Finally, the presence of left ventricular thrombosis was inversely related to the asynergy score. Conclusion These observations suggest that the presence of left ventricular thrombus is related to the extent of myocardial damage. Thrombolytic therapy reduces thrombus probably by salvaging myocardium at risk. (Eur Heart J 1996; 17: 421–428)

In a patient with sporadic atypical chest pain associated with dyspnea, stress Tc-99m MIBI imaging showed normal perfusion and inferoposterior hypoperfusion on the resting study. Although this reverse perfusion pattern was considered artifactual, the patient later had an acute myocardial infarction involving the same areas. Postinfarction stress Tc-99m MIBI imaging showed a nonreversible defect in the same area that, in the earlier study, showed a reverse perfusion pattern. The authors hypothesize that partial stenosis of the related artery with some nontransmural myocardial necrosis at the time of the initial study may be a possible cause of this peculiar Tc-99m MIBI perfusion pattern.

Objectives. In a prospective study we evaluated whether late recanalization of the left anterior descending coronary artery (LAD) affects ventricular volume and function after anterior myocardial infarction. Background. Persistent coronary occlusion after anterior myocardial infarction leads to ventricular dilation and heart failure. Methods. We studied 73 consecutive patients with acute anterior myocardial infarction as a first cardiac event; all had an isolated lesion or occlusion of the proximal LAD. Six patients died before hospital discharge. The 67 survivors were classified into two groups: group I (patent LAD and good distal flow, n = 40) and group II (LAD occlusion or subocclusion, n = 27). The 20 patients in group I who had significant residual stenosis and all patients in group II underwent elective percutaneous transluminal coronary angioplasty (PTCA) within 18 days of myocardial infarction. The procedure was successful in 17 patients in group I (group IB) and in 16 patients in group n (group IIA): in the remaining 11 patients of group II, patency could not be reestablished (group IIB). Left ventricular volumes, ejection fraction and a dysfunction score were measured by echocardiography on admission, before PTCA, at discharge and after 3 and 6 months. Results. Although cumulative ST segment elevation was similar in groups I and II, ejection fraction and dysfunction score were significantly worse in group II. However, ventricular function and volumes progressively improved in group IIA, whereas group IIB exhibited progressive deterioration of function (dysfunction score [mean +/- SD] increased from 21 +/- 6 to 25 +/- 8, p < 0.05; ejection fraction decreased from 43 +/- 10% to 37 +/- 11%, p < 0.05); and end-systolic volume increased from 34 +/- 10 to 72 +/- 28 ml/m(2), p < 0.05). Patients in group IIB also had worse effort tolerance, higher heart rate at rest, lower blood pressure and significantly greater prevalence of chronic heart failure. Conclusions. Delayed PTCA of an occluded LAD can frequently restore vessel patency. Success appears to be associated with better ventricular function and a lack of chronic dilation. Large randomized studies are warranted to evaluate the effect of delayed PTCA on late mortality.

Division of Cardiology and * Department of Nuclear Medicine, University of Milan, Instituto Scientifico H SanRaffaele, MilanObjective To evaluate the stress-redistribution myocardialperfusion pattern in patients with angina, positive exer-cise test and angiographically smooth coronary arteries(syndrome X).Design Prospective study.Patients and methods Twenty-five consecutive patients(seven males, mean age 54 ± 8 years) with typical angina,positive exercise test, normal coronary arteries and noinducible spasm, underwent stress-redistribution thallium-201 myocardial perfusion scintigraphy. Thirty-two consecu-tive patients (14 males, mean age 49 ± 7 years) with atypicalchest pain and negative exercise test, undergoing stress-redistribution thallium scan, served as controls.Results Exercise was discontinued for angina and/or ST-segment depression after 12 ± 3 min. Thallium stress imagesrevealed 40 hypoperfused segments in 27 patients (77%);after 4 h, 16 of these segments had completely normalized,10 remained unchanged, six exhibited partial reperfusionand eight worsened. Twenty-four patients (69%) exhibitedthallium reverse redistribution in 33 segments. Thirty-fourpatients (97%) had at least one hypoperfused segment inone of the two scintigraphic phases. Of the 24 patients withreverse redistribution, eight also underwent stress-rest99mTc-MIBI SPECT: six exhibited reduced tracer uptakethat was present at rest, but not on stress images, in thesame segments showing thallium reverse redistribution.Thallium stress images revealed four hypoperfused seg-ments in three controls (9%); at redistribution, one segmentnormalized, two remained unchanged and one exhibitedpartial reperfusion. Additionally, there were four newunderperfused segments appearing on redistribution in fourpatients (13%). Overall, there were seven controls (22%)with at least one hypoperfused myocardial segment in oneof the two scintigraphic phases.Conclusions Our study confirms that perfusion abnor-malities are present in most syndrome X patients. Addition-ally, the data show that reverse redistribution (a perfusiondefect that develops or becomes more evident on delayedimaging) is a common finding in these patients. The mecha-nisms of the phenomenon remain obscure: we suggest thatit is due to inhomogeneous perfusion, and the hyperaemicresponse induced by exercise masks resting underperfusionof certain areas.(Eur Heart J 1996; 17: 1482-1487)Key Words: Thallium myocardial scintigraphy, anginapectoris, normal coronary arteries, syndrome X, reverseredistribution.

Development of a perfusion defect on the 201Tl image from exercise to redistribution is referred to as reverse redistribution, a finding which has been previously associated with several conditions. We describe here two cases in which the reverse-redistribution phenomenon, observed in a routine stress-redistribution thallium-201 scan performed because of chest pain, was considered to be artifactual. Both patients subsequently developed a myocardial infarction in the areas showing the delayed perfusion defect. The potential clinical significance of the reverse-redistribution phenomenon in these two cases is discussed. When observed in patients with typical anginal pain, the reverse redistribution pattern should be considered a potential marker of tissue at risk in a region with previous, otherwise undetected, subendocardial infarction. In such patients the need for coronary angiography should be carefully considered.