Andrea Pozzati

Angiographic morphology in unstable angina and its relation to transient myocardial ischemia and hospital outcome

Complex stenosis morphology frequently occurs in patients with unstable angina pectoris. However, its relation to transient myocardial ischemia and hospital outcome has not been ascertained. To address this issue, 88 patients with significant (greater than or equal to 50%) coronary artery disease presenting with angina--new onset (n = 38), worsening (n = 20) or at rest (n = 30)-were studied. Patients with left main artery disease, normal coronary arteries or occlusion of the ischemia-related arteries were not included in the study. Continuous electrocardiographic recordings were obtained during the first 24 hours. Angiography was performed within 1 week from admission. Complex morphology was defined as any stenosis with irregular borders, overhanging edges or intracoronary thrombus. Only data referring to the in-hospital outcome were considered in this study. Adverse end points were sudden death, myocardial infarction and emergency revascularization. Analysis of the angiograms revealed a complex morphology in 58 patients (group 1). The remaining 30 patients served as control subjects (group 2). Thirty-two of the 58 group 1 patients had an unfavorable clinical outcome (positive predictive value, 55%). A similar outcome occurred in only 2 of the 30 group 2 patients (negative predictive value, 93%). Of the 32 group 1 patients who had an unfavorable clinical outcome, 29 had a cumulative duration of transient myocardial ischemia of greater than or equal to 60 minutes per 24 hours. A similar duration of ischemia, however, was observed in another 6 group 1 and in 8 group 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Vasotonic angina: A spectrum of ischemic sysdroms involving function abnormalities of the epicardial and microvascular coronary circulation

OBJECTIVES The present study was undertaken to investigate the response of large and small coronary arteries in a subgroup of patients with no or minimal coronary artery disease found to have objective signs of myocardial ischemia. BACKGROUND Many patients apparently have normal coronary arteries despite abnormal electrocardiographic (ECG) changes during spontaneous anginal attacks or exercise stress testing. METHODS Twenty-five patients with no or minimal (< 30% stenosis) coronary artery disease were chosen from a pool initially selected on the basis of spontaneous anginal attacks and ST segment shifts in the anterior leads. Of these, 10 were grouped as having variant angina (at least one episode of ST elevation) and the remaining 15 as having syndrome X (exercise-induced anginal pain, ST depression and reversible thallium abnormalities). Data were compared with those obtained in 10 patients with stable angina and documented coronary artery disease. Eighteen patients with supraventricular arrhythmias and normal coronary arteries served as control patients. Patients showing focal spasm during ergonovine testing were not included in the subsequent angiographic analysis. Great cardiac vein blood flow, aortic pressure and changes in coronary artery diameter were measured at rest and 2 to 4 min after hyperventilation in the remaining study group. The same procedure was repeated after sublingual administration of 0.3 mg of nitroglycerin in eight patients (four with syndrome X and four with variant angina). RESULTS Hyperventilation induced diffuse epicardial coronary diameter reduction, which was marginal in control patients (9 +/- 4%) and those with coronary artery disease (5 +/- 3%) but severe (p < 0.001) in those with variant angina (28 +/- 14%) or syndrome X (25 +/- 13%). Concomitant determination of coronary blood flow showed significant (p < 0.001) decreases in those with variant angina (25 +/- 11%) and syndrome X (28 +/- 10%) but not in control patients (5 +/- 8%) or those with coronary artery disease (4 +/- 5%). Changes in great cardiac vein blood flow during hyperventilation were similar before and after nitroglycerin. CONCLUSIONS These findings indicate that vasoconstrictor stimuli may trigger a diffuse abnormal response of both epicardial and resistance vessels in some patients with chest pain and angiographically normal coronary arteries. Patients showing such diffuse vasoconstrictor abnormalities are suggested to have a single pathogenetic entity with a spectrum of ECG manifestations ranging from ST depression to ST elevation.

Relation of Severity of Symptoms to Transient Myocardial Ischemia and Prognosis in Unstable Angina

OBJECTIVES This study was undertaken to compare the relative power of the severity of angina versus that of any other clinical, electrocardiographic (ECG) and angiographic findings in predicting the risk of subsequent in-hospital coronary events in patients admitted to the coronary care unit for treatment of unstable angina. BACKGROUND The presence or absence of chest pain has traditionally been used to guide management and therapy of unstable angina. However, recent studies raised the possibility that the cumulative duration of ischemia may be an additional index of prognosis. METHODS We studied 104 consecutive patients admitted to the coronary care unit because of unstable angina. Diaries of symptoms were accurately kept. All patients underwent Holter ambulatory ECG monitoring during the 1st 24 h and angiography within 1 week of admission. RESULTS During the hospital stay, 41 patients (group 1) had subsequent coronary events; the remaining 63 patients (group 2) had a good clinical outcome. Recurrence of chest pain after admission was observed in 76% of patients: 36 of the 41 group 1 patients (sensitivity 88%) and 43 of the 63 group 2 patients (specificity 32%). Anginal scores (frequency and persistence of pain, duration of each single episode and pain-free interval) showed high specificity but low sensitivity for detecting evolution toward subsequent coronary events. On Holter monitoring, the duration/24 h of the total number of ischemic episodes was consistently greater in group 1 than in group 2. A cumulative duration of ischemia > or = 60 min/24 h was observed in 34 of the 41 group 1 patients (sensitivity 83%) but in only 16 of the 63 group 2 patients (specificity 75%). High risk coronary artery lesions (left main coronary artery disease or complex stenosis) were detected in 36 of the 41 group 1 patients and in 26 of the 63 group 2 patients. CONCLUSIONS Transient myocardial ischemia detected by Holter monitoring, but not chest pain, is the best predictor of unfavorable short-term clinical outcome. The decision to perform early angiography and revascularization cannot be based on symptoms alone.

The paradox of nitrates in patients with angina pectoris and angiographically normal coronary arteries.

Abstract Patients with angina pectoris found to have angiographically normal coronary arteries and no evidence of coronary spasm or ventricular hypertrophy present a management dilemma to all physicians. Most of these patients have an inadequate vasodilatory capacity of the coronary microcirculation, 1 which may result in ischemia during increases in myocardial oxygen demand; accordingly, they could benefit from either vasodilator agents or drugs that reduce myocardial oxygen demand. Nitrates are among the oldest, effective antianginal pharmacologic agents; their mechanisms of action are capable of affecting both the supply and demand side of the metabolic equation of the heart, 2 which appeared promising in regard to treatment of this syndrome. Therefore, the present study was performed to investigate the effects of isosorbide dinitrate on coronary hemodynamics and anginal threshold in a group of patients with the aforementioned set of findings, as well as reversible thallium abnormalities during exercise.

Prognostic significance of silent myocardial ischemia in variant angina pectoris.

The present study investigates the prognostic significance of silent myocardial ischemia in variant angina. Forty-eight-hour Holter monitoring and coronary angiography were performed in 54 patients with transient ST elevation and no history of myocardial infarction admitted to the coronary care unit for worsening of symptoms. Coronary artery spasm was documented in most of these patients. Over the subsequent month, 20 patients (group 1) had a major coronary event (2 died, 6 had nonfatal myocardial infarction and 12 had urgent coronary revascularization), and the remaining 34 patients (group 2) had a good clinical outcome. From 2,578 hours of recording, 547 ischemic episodes were identified of which only 9% were associated with angina. The mean daily number of ST elevation in group 1 was similar to that in group 2 (4.8 +/- 5.1 vs 4.1 +/- 4.6; p = not significant). Conversely, the mean daily duration of such ischemic episodes was consistently greater in group 1 than in 2 (79 +/- 36 vs 37 +/- 25 minutes; p less than 0.005). The occurrence of greater than or equal to 1 long-lasting (greater than or equal to 10 minutes) episode of ST elevation was observed in 18 of 20 patients in group 1 (sensitivity 90%), but only in 4 of 34 in group 2 (specificity 88%). Significant coronary atherosclerosis (greater than 50% stenoses) was found at angiography in 18 of 20 patients in group 1, and in 18 of 34 in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute rupture of sinus of valsalva in the right atrium during attempted pregnancy.

A 36-year-old woman was admitted to the first-aid unit for sudden dyspnea and palpitation. Significant cardiac findings were a loud continuous murmur (2–3/6 on Levine’s scale) at the second intercostal space on the left sternal border, absent in prior examination. Gas analysis showed transient hypoxemia with normocapnia. Hypoxemia and symptoms rapidly normalized. D-dimer measurement was positive. An electrocardiogram showed negative T waves on antero-lateral precordial leads.

Effect of oral levodopa and carbidopa on coronary spasm in variant angina pectoris

The effect of oral administration of 500 mg of levodopa with 50 mg of carbidopa, a peripheral dopadecarboxylase inhibitor, on coronary vasomotion during vasoconstrictor stimuli was examined in 15 patients with variant angina presenting with hyperventilation-induced myocardial ischemia. Patients were studied during 3 noninvasive sessions and 1 angiographic session. In all sessions the basic protocol consisted of provocation of coronary spasm by hyperventilation before and 2 hours after levodopa and carbidopa administration. During angiography, great cardiac vein blood flow, right atrial and aortic pressures were measured, and coronary angiograms were recorded at baseline and 1 to 4 minutes after each hyperventilation. Samples for dopamine plasma levels were drawn before and throughout the studies. In 3 selected patients, levodopa and carbidopa were associated with 30 mg of domperidone, an antagonist of dopamine peripheral receptors. Levodopa and carbidopa consistently prevented the occurrence of ischemia after hyperventilation in 6 of the 15 patients. This was due to inhibition of local coronary spasm in 2 patients and reduced coronary constriction in 4. Ischemia due to hyperventilation was still prevented despite addition of domperidone with levodopa and carbidopa. Plasma dopamine levels were 23 +/- 15 before and 739 +/- 284 pg/ml 2 hours after administration of levodopa and carbidopa. These findings are consistent with either a decreased central dopaminergic activity and associated disregulation of vasomotor tone, or a peripheral vasodilatory effect of increasing dopamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Epicardial Coronary Artery Responses In Patients With Angina And Normal Coronary Arteriograms

The mechanism responsible for chest pain in patients with normal coronary arteries is still a matter of debate. In most cases the pain is non-cardiac1, often musculo-skeletal or oesophageal in origin2. In other patients evidence exists for inducible ischaemia associated with dynamic coronary dysfunction3. The cause of this dysfunction may not be the same in all patients. In some patients the functional abnormality may be limited to the small coronary arteries, whereas in others the entire coronary tree may be involved.

Invasive monitoring of coronary blood flow in acute myocardial infarction: pathogenetic and therapeutic relevance

The need to develop a reliable marker of reperfusion is important in view of the large number of pts in whom thrombolysis is now likely to be used. We measured coronary blood flow (CBF; thermodilution technique) in 12 pts presenting with acute myocardial infarction (AMI) and ST elevation in the anterior leads. After application of i.v. thrombolytic therapy (urokinase, 2 mil IU), CBF was measured every 30 min for 4 hrs and then every 4 hrs for 20 hrs. Coronary blood flow increased by more than 30% in 9 pts (G1): from 86±24 to 126±46 ml/min; p < 0.001. No significant changes were seen in the remaining 3 pts (G2). Coronary angiography was performed in all pts and showed patency of the infarct-related artery in 8/9 G1 pts (89%) and occlusion in the remaining four pts. We conclude that measurement of CBF is a relatively simple technique that appears both sensitive and specific in detecting coronary reperfusion in anterior AMI.