A case of unprovoked, precarious, patent foramen ovale protuberance.

This is a case of a precarious thrombotic mass straddling a patent foramen ovale which had already embolised to the pulmonary circulation. The diagnosis was initially deceptive and management challenging. LEARNING POINTS: Echocardiography is mandated and can change management in haemodynamically unstable patients with pulmonary emboli.Pulmonary embolism can be life-threatening.The authors propose that urgent cardiac surgery is the safest treatment in the setting of highly mobile, large volume, intra-cardiac thrombus.

Stem cells to repair the broken heart: much ado about nothing?

The long promised benefits of using stem cells for myocardial repair are still awaited.

Late opening of the infarct related artery: an open or shut case?

Is there a place for the late opening of infarct related arteries, beyond the time window for myocardial salvage?

Ischaemic preconditioning and myocardial adaptation to serial intracoronary balloon inflation: cut from the same cloth?

Elective percutaneous coronary intervention fulfils many of the criteria needed of a clinical model of ischaemic preconditioning. But is this really a reflection of the laboratory phenomenon of ischaemic preconditioning?

Percutaneous closure of an iatrogenic puncture of the aortic arch.

We report on the management of a rare complication of a vascular sheath being placed inadvertently in the aorta rather than in the venous system following thrombolytic therapy administration in a patient presenting with an acute myocardial infarction and complete heart block.

Myocardial contrast echocardiography is superior to other known modalities for assessing myocardial reperfusion after acute myocardial infarction.

BACKGROUND: Angiographic flow measurements do not define perfusion accurately at a microvascular level, so other techniques which assess flow at a tissue level are to be preferred. OBJECTIVES: To compare intravenous myocardial contrast echocardiography (MCE) with other methods of assessing microvascular reperfusion for their ability to predict left ventricular function at one month after acute myocardial infarction. DESIGN: 15 patients underwent primary percutaneous coronary angioplasty for acute myocardial infarction, with restoration of TIMI grade 3 flow. Corrected TIMI frame count (cTFC), myocardial blush grade (MBG), and percentage ST segment resolution at 90 and 180 minutes were recorded. Baseline regional wall motion score index (WMSI) and regional contrast score index (RCSI) were obtained 12-24 hours after the procedure, with a final regional WMSI assessment at one month. RESULTS: Mean (SD) cTFC was 27 (9.4), and ST segment resolution was 69 (22)% at 90 minutes and 77 (20)% at 180 minutes. MBG values were 0 in six patients, 2 in two, and 3 in seven. Baseline regional WMSI, RCSI, and follow up WMSI were 2.7 (0.71), 1.5 (0.71), and 1.6 (0.73), respectively. The correlation coefficient between RCSI and follow up WMSI was 0.82 (p = 0.0012). Peak CK correlated with follow up WMSI (R = 0.80). None of the other reperfusion assessment techniques correlated significantly with follow up WMSI. Multiple regression analysis showed that a perfused hypokinetic or akinetic segment was 50 times more likely to recover function than a non-perfused segment. MCE predicted segmental myocardial recovery with a sensitivity of 88%, a specificity of 74%, and positive and negative predictive values of 83% and 81%, respectively. CONCLUSIONS: MCE is currently the best and most accurate measure of reperfusion at a microvascular level and an excellent predictor of left ventricular function at one month following acute myocardial infarction.

Antiarrhythmic and anti-ischaemic effects of angina in patients with and without coronary collaterals.

OBJECTIVE: To determine whether the changes in the manifestations of myocardial ischaemia during sequential angina episodes caused by exercise or coronary artery occlusion are collateral dependent. METHODS: 40 patients awaiting percutaneous transluminal coronary angioplasty for an isolated left anterior descending artery stenosis underwent three sequential treadmill exercise tests, with the second exertion separated from the first by 15 minutes, and from the third by 90 minutes; 28 patients subsequently completed two (> 180 s) sequential intracoronary balloon inflations with measurement of collateral flow index from mean coronary artery wedge, aortic, and coronary sinus pressures. RESULTS: On second compared with first exercise, time to 0.1 mV ST depression (mean (SD): 340 (27) v 266 (25) s) and rate-pressure product at 0.1 mV ST depression (22 068 (725) v 19 586 (584) beats/min/mm Hg) were increased (all p < 0.005), while angina and ventricular ectopic beat frequency were diminished (p < 0.05). This advantage, which had waned by the third effort, was independent of collateral flow index. Similarly, at the end of the second compared with the first coronary occlusion, ventricular tachycardia (21% v 0%, p < 0.05), ST elevation (0.47 (0.07) v 0.33 (0.05) mV, p < 0.005), and angina severity (6.1 (0.7) v 4.6 (0.7) units, p < 0.005) were reduced despite similar collateral flow indices. CONCLUSIONS: In patients with coronary artery disease, ventricular arrhythmias, ST deviation, and angina are reduced during a second exertion or during a second coronary occlusion. This protective effect can occur independently of collateral recruitment. These characteristics, together with the breadth and temporal pattern of protection, are consistent with ischaemic preconditioning.

Postinfarction left ventricular remodeling: a pathophysiological and therapeutic review.

Over the last 50 years, studies investigating the pathogenesis of left ventricular dysfunction have resulted in many potential therapeutic targets being identified and novel classes of drugs designed to treat this condition. Despite this, the long-term prognosis of patients with clinical heart failure remains poor with mortality rates equivalent to many terminal malignancies. This article reviews our present understanding of the pathophysiology of post-infarction left ventricular dysfunction and provides a rationale for current drug usage, drugs undergoing clinical trials and compounds still under pre-clinical development. In addition, the complexities involved in deciphering intra-cellular signalling pathways mediating ventricular hypertrophy which may form the basis of future treatments are also discussed.

Reversible left ventricular dysfunction: does it affect clinical practice and does it matter?

There is substantial evidence that many patients with impaired left ventricular function secondary to coronary artery disease may have hibernating or stunned myocardium. The identification of these patients is important, as revascularisation is associated with an improvement in function, and there is some evidence that revascularisation of these patients will actually improve prognosis. The most useful investigations for the identification of reversible left ventricular dysfunction are dobutamine echocardiography, thallium scanning and, although not available in many centres, PET scanning.

Effect of magnesium sulphate in patients with unstable angina. A double blind, randomized, placebo-controlled study.

AIMS: Administration of intravenous magnesium sulphate has been shown to be protective during acute myocardial ischaemia and it may therefore have beneficial effects in unstable angina. The purpose of this study was to assess the effects of a 24-h infusion of magnesium in patients with unstable angina. METHODS AND RESULTS: Patients who presented with unstable angina with electrocardiographic changes were randomized to receive a 24-h intravenous infusion of magnesium or placebo within 12 h of admission. The primary endpoint was myocardial ischaemia, as assessed by 48 h Holter monitoring. Resting 12-lead ECGs, creatine kinase-MB release and urinary catecholamines were also assessed. Patients were followed for 1 month. Thirty-one patients received magnesium sulphate and 31 placebo. Baseline characteristics and extent of coronary disease were similar in both groups. On 48 h Holter monitoring, 14 patients (50%) had transient ST segment shifts in the magnesium group vs 12 patients (46%) in the placebo group. However, there were fewer ischaemic episodes in the magnesium group (51 vs 101, P < 0.001) and there was a trend towards an increase in the total duration of ischaemia in the placebo group compared to the magnesium group in the second 24 h (2176 min vs 719 min respectively, P = 0.08). Regression of T wave changes on the 24 h ECG occurred more frequently in patients who received magnesium compared to those treated with placebo (11 patients vs 0 patients respectively, P < 0.005). Creatine kinase-MB release was significantly less at 6 and 24 h in patients who received magnesium compared to those treated with placebo. Catecholamine excretion was lower in patients treated with magnesium than in those treated with placebo (adrenaline: 1.05 +/- 0.16 vs 1.61 +/- 0.32 ng.mmol-1 creatinine; noradrenaline: 9.99 +/- 1.82 vs 18.48 +/- 2.41 ng.mmol-1 creatinine respectively in the first 12 h sample, P < 0.05). CONCLUSIONS: Intravenous magnesium reduces ischaemic ECG changes, creatine kinase-MB release and urinary catecholamine excretion in the acute phase of unstable angina. Thus, magnesium may be a beneficial additional therapy for these patients. Further studies are required to confirm these finding.

Selection of dichotomy limits for multifactorial prediction of arrhythmic events and mortality in survivors of acute myocardial infarction.

AIMS: To evaluate the predictive value and optimum dichotomy limits for different combinations of prognostic indicators for the prediction of arrhythmic events and cardiac mortality in post-infarction patients. BACKGROUND: Studies of new interventions based on risk stratification after myocardial infarction have often used a single variable as a predictor of risk. However, whether the dichotomy limits of these single variables, derived from univariate analyses, should be altered when such variables are combined for the prediction of risk after myocardial infarction has not been examined. METHODS: Left ventricular ejection fraction, signal-averaged electrocardiography, heart rate variability index, mean heart rate and ventricular extrasystole frequency were recorded pre-discharge in 439 survivors of their first myocardial infarction. Arrhythmic events and cardiac mortality were recorded during 1 year (range 1-6 years) follow-up. RESULTS: During follow-up for at least 1 year, there were 25 cardiac deaths and 23 arrhythmic events. Different optimum dichotomy limits were obtained for the prediction of cardiac mortality vs arrhythmic events, for different combinations of variables, for different selected levels of sensitivity and for different numbers of variables abnormal before identification of those at risk. The dichotomy limit of the heart rate variability index for the prediction of events appeared to be the least affected by the inclusion of other variables. For example, when predicting arrhythmic events using combinations of left ventricular ejection fraction and/or heart rate variability, the optimum dichotomy limits when each variable was used alone was 32% and 18 units respectively; 43% and 18 units when either left ventricular ejection fraction or heart rate variability are required to be abnormal, and 52% and 19 units when both are required to be abnormal before identification of those at risk of arrhythmic events. CONCLUSIONS: Dichotomy limits derived from univariate analyses do not optimally predict events when used in the multivariate setting. Risk stratification can be improved by using several variables in combination and is further improved by using dichotomy limits of these variables which are different from those used in or derived from univariate analyses.