Effect of coronary occlusion during percutaneous transluminal angioplasty in humans on left ventricular chamber stiffness and regional diastolic pressure-radius relations

A modified intraventricular balloon method for functional assessment of hearts from donation after circulatory death

Objective

Functional assessment of hearts during ex-vivo heart perfusion is not well-established. Conventional intraventricular balloon methods for large animals sacrifice the mitral valve. This study assessed the effectiveness of the modified intraventricular balloon method in comparison with other modalities used during working mode in juvenile pigs.

Methods

Following asphyxia circulatory arrest, hearts were ischemic for 15 minutes and then reperfused on an ex-vivo device for 2 hours before switching to working mode. Left ventricular pressure was continuously measured during reperfusion by a saline-filled balloon fixated in the left atrium. Spearman Correlation Coefficients with linear regression lines with confidence intervals were analyzed.

Results

Maximum dp/dt at 90 minutes of reperfusion and minimum dp/dt at 60 minutes of reperfusion showed a moderate positive correlation to that in working mode, respectively (Rs = 0.61, P = .04 and Rs = 0.60, P = .04). At 60 minutes of reperfusion, minimum dp/dt showed moderate positive correlation to tau (Rs = 0.52, P = .08). Myocardial oxygen consumption during reperfusion consistently decreased at least 30% compared to working mode (at 90 minutes as the highest during reperfusion, 3.3 ± 0.8; in working mode, 5.6 ± 1.4, mLO2/min/100 g, P < .001).

Conclusions

Functional parameters of contractility and relaxation measured during reperfusion by the modified balloon method showed significant correlations to respective parameters in working mode. This mitral valve sparing technique can be used to predict viability and ventricular function in the early phase of ex-vivo heart perfusion without loading the heart during working mode.

Treatment of HFpEF beyond the SGLT2-Is: Does the Addition of GLP-1 RA Improve Cardiometabolic Risk and Outcomes in Diabetic Patients?

Heart failure with preserved ejection fraction (HFpEF) is a common clinical syndrome frequently seen in elderly patients, the incidence of which is steadily increasing due to an ageing population and the increasing incidence of diseases, such as diabetes, hypertension, obesity, chronic renal failure, and so on. It is a multifactorial disease with different phenotypic aspects that share left ventricular diastolic dysfunction, and is the cause of about 50% of hospitalizations for heart failure in the Western world. Due to the complexity of the disease, no specific therapies have been identified for a long time. Sodium-Glucose Co-Transporter 2 Inhibitors (SGLT2-Is) and Glucagon-Like Peptide Receptor Agonists (GLP-1 RAs) are antidiabetic drugs that have been shown to positively affect heart and kidney diseases. For SGLT2-Is, there are precise data on their potential benefits in heart failure with reduced ejection fraction (HFrEF) as well as in HFpEF; however, insufficient evidence is available for GLP-1 RAs. This review addresses the current knowledge on the cardiac effects and potential benefits of combined therapy with SGLT2-Is and GLP-1RAs in patients with HFpEF.

Coronary Artery Disease and Heart Failure With Preserved Ejection Fraction: The ARIC Study

Background Whether coronary artery disease (CAD) is a significant risk factor for heart failure (HF) with preserved ejection fraction (HFpEF) is unclear. Methods and Results Among 9902 participants in the ARIC (Atherosclerosis Risk in Communities) study, we assessed the association of incident CAD with subsequent incident HFpEF (left ventricular ejection fraction [≥50%]) and HF with reduced ejection fraction (HFrEF; left ventricular ejection fraction <50%) using survival models with time-updated variables. We also assessed the extent to which echocardiographic correlates of prevalent CAD account for the relationship between CAD and incident HFpEF. Over 13-year follow-up, incident CAD developed in 892 participants and 178 subsequently developed HF (86 HFrEF, 71 HFpEF). Incident HFrEF and HFpEF risk were both greatest early after the CAD event. At >1 year post-CAD event, adjusted incidence of HFrEF and HFpEF were similar (7.2 [95% CI, 5.2-10.0] and 6.7 [4.8-9.2] per 1000 person-years, respectively) and CAD remained predictive of both (HFrEF: hazard ratio, 2.76 [95% CI, 1.99-3.84]; HFpEF: 1.85 [1.35-2.54]) after adjusting for demographics and common comorbidities. Among 4779 HF-free participants at Visit 5 (2011-2013), the 490 with prevalent CAD had lower left ventricular ejection fraction and higher left ventricular mass index, E/e', and left atrial volume index (all P<0.01). The association of prevalent CAD with incident HFpEF post-Visit 5 was not significant after adjusting for echocardiographic measures, with the greatest attenuation observed for left ventricular diastolic function. Conclusions CAD is a significant risk factor for incident HFpEF after adjustment for demographics and common comorbidities. This relationship is partially accounted for by echocardiographic alterations, particularly left ventricular diastolic function.

Re-evaluating methods reporting practices to improve reproducibility: an analysis of methodological rigor for the Langendorff whole-heart technique

In recent decades, the scientific community has seen an increased interest in rigor and reproducibility. In 2017, concerns of methodological thoroughness and reporting practices were implicated as significant barriers to reproducibility within the preclinical cardiovascular literature, particularly in studies employing animal research. The Langendorff, whole-heart technique has proven to be an invaluable research tool, being modified in a myriad of ways to probe questions across the spectrum of physio- and pathophysiologic function of the heart. As a result, significant variability in the application of the Langendorff technique exists. This literature review quantifies the different methods employed in the implementation of the Langendorff technique and provides brief examples of how individual parametric differences can impact the outcomes and interpretation of studies. From 2017-2020, significant variability of animal models, anesthesia, cannulation time, and perfusate composition, pH, and temperature demonstrate that the technique has diversified to meet new challenges and answer different scientific questions. The review also reveals which individual methods are most frequently reported, even if there is no explicit agreement upon which parameters should be reported. The analysis of methods related to the Langendorff technique suggests a framework for considering methodological approach when interpreting seemingly contradictory results, rather than concluding that results are irreproducible.

Relief of Ischemia in Ischemic Cardiomyopathy

PURPOSE OF THE REVIEW

Ischemic heart disease is among the most common causes of morbidity and mortality worldwide. In its stable manifestation, obstructing coronary artery stenoses prevent myocardial blood flow from matching metabolic needs of the heart under exercise conditions, which manifests clinically as dyspnea or chest pain. Prolonged bouts of ischemia may result in permanent myocardial dysfunction, heart failure, and eventually reduced survival. The aim of the present work is to review currently available approaches to provide relief of ischemia in stable coronary artery disease (CAD).

RECENT FINDINGS

Several pharmacological and interventional approaches have proven effectiveness in reducing the burden of ischemia in stable CAD and allow for symptom control and quality of life improvement. However, substantial evidence in favor of improved survival with ischemia relief is lacking, and recently published randomized controlled trial suggests that only selected groups of patients may substantially benefit from this approach. Pharmacological treatments aimed at reducing ischemia were shown to significantly reduce ischemic symptoms but failed to provide prognostic benefit. Myocardial revascularization is able to re-establish adequate coronary artery flow and was shown to improve survival in selected groups of patients, i.e., those with significant left main CAD or severe left ventricular dysfunction in multivessel CAD. Outside the previously mentioned categories, revascularization appears to improve symptoms control over medical therapy, but does not confer prognostic advantage. More studies are needed to elucidate the role of systematic invasive functional testing to identify individuals more likely to benefit from revascularization and to evaluate the prognostic role of chronic total occlusion recanalization.

Impaired coronary microcirculation is associated with left ventricular diastolic dysfunction in end-stage chronic kidney disease patients

INTRODUCTION

Coronary vascular dysfunction, as assessed by coronary flow reserve (CFR) in the left anterior descending coronary artery, is found in various conditions including end-stage chronic kidney disease (CKD). Currently, we investigated the associations of CFR with echocardiographic indices of systolic and diastolic cardiac function and identified independent predictors of CFR in hemodialysis patients.

METHODS

End-stage CKD patients treated with hemodialysis (n = 29) without known cardiovascular disease were recruited from a Hemodialysis Unit in Northwestern Greece. A thorough echocardiographic evaluation including CFR measurement following dipyridamole infusion was performed in all participants. Arterial stiffness was assessed by measurement of carotid-femoral pulse wave velocity and aortic augmentation index.

RESULTS

The mean age of the patients was 63 years, and mean duration of hemodialysis was 2.9 years. CFR was 1.60 ± 0.37 while dipyridamole caused a significant increase in E'_sep , S_lat , E'_lat , and Stroke volume (P < .05 for all). Independent predictors of CFR were posterior wall thickness (B -0.408, P = .013) and dipyridamole-induced changes in Tei index (B -0.425, P = .007). A severely decreased CFR < 1.5 was observed in 52% of the patients. E/E' ratio (B 10.84, P = .014) was the single independent predictor of severely decreased CFR.

CONCLUSIONS

In end-stage CKD patients on hemodialysis without known cardiovascular disease, impaired coronary vascular function was prevalent and related to increased left ventricular wall thickness, increased filling pressures, and dipyridamole-induced deteriorated myocardial function independently of the presence of wall-motion abnormalities. Further studies are required to clarify the prognostic role of dipyridamole-induced cardiac changes in hemodialysis patients.

The prognostic role of myocardial strain indices and dipyridamole stress test in renal transplantation patients

INTRODUCTION

Renal transplantation (RT) increases survival in end-stage kidney disease patients but cardiovascular diseases remain the leading cause of morbidity and mortality. We evaluated the role of myocardial strain (2DSTE) indices and dipyridamole-induced (DIPSE) changes in echocardiographic parameters at baseline for the prediction of clinical events and echocardiographically assessed deterioration of cardiac function in a RT population.

METHODS

Forty-five RT patients underwent an echocardiographic study at baseline including 2DSTE and DIPSE. If no cardiovascular/renal event occurred, patients were investigated at 3-year follow-up; eight patients presented a clinical event while 37 patients were re-evaluated.

RESULTS

Coronary flow reserve (CFR) was abnormal in 24% of the population. DIPSE induced improvements in classic and 2DSTE systolic and diastolic echocardiographic indices including TWIST, UNTWIST, global longitudinal strain (GLS), and circumferential strain (P < .05 for all). Compared to baseline, deteriorations in E/E', LVEF, E', and TWIST were observed at follow-up (P < .05 for all). DIPSE-induced changes in GLS, global radial strain, and LVEF were associated with changes in these indices at follow-up (P < .05 for all). Higher LV mass index, E/E', and lower MAPSE, E', and CFR at baseline were associated with the occurrence of clinical events at follow-up (P < .05 for all).

CONCLUSIONS

In RT patients, coronary vascular dysfunction (ie, low CFR) was associated with the occurrence of adverse events. DIPSE-induced changes in myocardial strain and classic echocardiographic indices could identify individuals with a subclinical deterioration in cardiac function at follow-up. This may indicate that DIPSE could serve as a means to assess myocardial reserve in this population.

Left ventricular concentric remodelling and functional impairment in women with ischaemia with no obstructive coronary artery disease and intermediate coronary flow reserve: a report from the WISE-CVD study

AIMS

Women with evidence of ischaemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). Although invasively measured coronary flow reserve (CFR) is useful for the diagnosis of CMD, intermediate CFR values are often found of uncertain significance. We investigated myocardial flow reserve and left ventricular (LV) structural and functional remodelling in women with suspected INOCA and intermediate CFR.

METHODS AND RESULTS

Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) study participants who had invasively measured intermediate CFR of 2.0≤ CFR ≤3.0 (n = 125) were included for this analysis. LV strain, peak filling rate (PFR) and myocardial perfusion reserve index (MPRI) were obtained by cardiac magnetic resonance imaging. Participants were divided: (i) Group 1 (n = 66) high MPRI ≥ 1.8, and (ii) Group 2 (n = 59) low MPRI < 1.8. The mean age was 54 ± 12 years and CFR was 2.46 ± 0.27. MPRI was significantly different but CFR did not differ between groups. LV relative wall thickness (RWT) trended higher in Group 2 and circumferential peak systolic strain and early diastolic strain rate were lower (P = 0.039 and P = 0.035, respectively), despite a similar LV ejection fraction and LV mass. PFR was higher in Group 1 and LV RWT was negatively related to PFR (r = -0.296, P = 0.001).

CONCLUSIONS

In women with suspected INOCA and intermediate CFR, those with lower MPRI had a trend towards more adverse remodelling and impaired diastolic LV function compared with those with higher MPRI. CFR was similar between the two groups. These findings provide evidence that both coronary microvessel vasomotion and structural and functional myocardial remodelling contribute to CMD.

Diastolic dysfunction predicts the risk of contrast-induced nephropathy and outcome post-emergency percutaneous coronary intervention in AMI patients with preserved ejection fraction

Patients with acute myocardial infarction (AMI) and reduced left ventricular ejection fraction (LVEF) are at high risk of contrast-induced nephropathy (CIN). However, the risk factors of CIN in AMI patients with preserved LVEF remain largely unknown now. The present study explored the relationship between LV diastolic function and CIN in this patient cohort. The present prospective cohort study enrolled 379 AMI patients with preserved LVEF (≥ 50%) who underwent emergency percutaneous coronary interventions (PCI). Transthoracic echocardiography was performed before PCI using a portable echocardiography system. Diastolic function was graded as normal, indeterminate and diastolic dysfunction according to the current recommendation of the American Society of Echocardiography and the European Association of Cardiovascular Imaging. A total of 88 patients (23.2%) developed CIN. Multivariate logistic regression analysis showed that both diastolic dysfunction (DD) and the mitral E velocity to mitral annular tissue Doppler E' velocity ratio (E/E') were independent predictors of CIN (P < 0.001). Other independent risk factors of CIN included increased Mehran score, ST-segment-elevation myocardial infarction, higher HbA1c and left anterior descending lesion, as well as the use of diuretics. Multivariate Cox regression analysis found that CIN, DD, higher N-terminal pro-B-type natriuretic peptide and HbA1c were independent predictors of MACE 2 years after AMI. Diastolic dysfunction determined before emergency PCI is linked with increased risk of CIN in AMI patients with preserved LVEF. CIN and diastolic dysfunction are independent predictors of MACE at 2 years in this patient cohort.

Impaired Diastolic Recovery after Acute Myocardial Infarction as a Predictor of Adverse Events

BACKGROUND

To investigate the impact of left ventricular (LV) diastolic functional recovery on major adverse cardiac events (MACE) 6 months after acute myocardial infarction (AMI) in patients with preserved LV systolic function.

METHODS

A total 463 patients with preserved LV systolic function at 6 months after an AMI were divided into two groups based on the extent of diastolic recovery assessed by echocardiography: group I (n = 241) showed improving diastolic function and group II (n = 222) did not. MACE included death, recurrent myocardial infarction, and rehospitalization due to heart failure, and these events were compared with the patients' characteristics at baseline.

RESULTS

Compared with group I, the patients in group II were older and had a higher prevalence of hypertension and diabetes. Blood levels of hemoglobin and triglyceride were lower in group II, whereas the levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and of high-sensitivity C-reactive protein were higher in this group than in group I. MACE were significantly more frequent in group II than in group I. Age, elevated NT-proBNP, and impaired diastolic recovery were significant independent predictors of MACE.

CONCLUSION

Despite improvement in LV systolic function, LV diastolic function had not improved in 222 patients (47.9%) by the 6-month follow-up after the index AMI, and impaired diastolic functional recovery was found to be an independent predictor of MACE. Evaluation of diastolic function would be a useful way to stratify risk in patients discharged after an index AMI.

The prognostic impact of diastolic dysfunction in patients with chronic heart failure and post-acute myocardial infarction: Can age-stratified E/A ratio alone predict survival?

OBJECTIVE

To determine the prognostic implications of diastolic filling grades and identify whether age-stratified E/A ratio alone can identify patients at high risk of death post-AMI and HF. We hypothesized that in response to ageing and pathology, a normal E/A (>1) could be considered abnormal in patients post-AMI older than 65years, and that in patients with symptomatic HF, a normal E/A always represents advanced diastolic dysfunction.

METHODS AND RESULTS

This is a sub-analysis of the Meta-analysis Research Group in Echocardiography (MeRGE) which combined individual patient data from 30 prospective studies and demonstrated that restrictive filling was an important and independent predictor of all-cause mortality. This sub-analysis is restricted to those studies in which continuous E/A data were available (20 studies) and includes a total of 3082 AMI and 2321 HF patients. Patients were classified at the time of echocardiography into four filling patterns: normal, abnormal relaxation, pseudonormal, and restrictive filling. Post-AMI patients were divided into four groups on the basis of age and E/A, while patients with HF were classified into three groups, based on only E/A. Mortality across groups was compared using Kaplan-Meier survival analysis and Cox proportional hazards. In multivariable analyses in the AMI patients, age-stratified E/A was an independent predictor of outcome (HR 1.43 (95% CI: 1.31-1.56)), and in the HF cohort, E/A was confirmed as an independent predictor of mortality (HR 1.12 (95% CI 1.09-1.16)) alongside age and ejection fraction.

CONCLUSIONS

Age-stratified E/A is an independent predictor of mortality after AMI and in HF patients, regardless of left ventricular ejection fraction, age and gender. E/A ratio could be a first step echocardiographic risk stratification, which could precede and indicate the need for more advanced diagnostic and prognostic considerations in high-risk AMI and HF patients.

Temporal analysis of regional strain rate during adenosine triphosphate stress before and after percutaneous coronary interventions

Regional myocardial ischemia is thought to be characterized by diastolic dysfunction. We aimed to clarify whether temporal analysis of strain rate (SR) index derived from two-dimensional speckle-tracking echocardiography (2DTE) can assess the regional myocardial ischemia or not. Forty-two patients with significant coronary stenoses were referred for percutaneous coronary intervention (PCI). 2DTE was performed before and a day after PCI. Time from aortic valve closure to peak early diastolic longitudinal SR ∆(TAVC-E SR) was measured both at baseline and during adenosine triphosphate (ATP) infusion. TAVC-E SR was calculated as TAVC-E SR during ATP infusion subtracted by TAVC-E SR at baseline. In forty-five target ischemic regions, TAVC-E SR at baseline was significantly longer than that of control regions (166 ± 28 vs. 136 ± 32 ms, P < 0.0001). TAVC-E SR in target ischemic regions significantly prolonged during ATP stress to 221 ± 37 ms (P < 0.0001), while it did not change in control regions. Immediately after PCI, TAVC-E SR in target regions significantly decreased to 135 ± 27 ms, P < 0.0001 without prolongation during ATP stress. Receiver operating characteristic curves demonstrated that ∆TAVC-E SR could assess regional myocardial ischemia by a cutoff criterion of 14 ms with sensitivity of 93% and specificity of 95%. 2DTE-derived TAVC-E SR significantly increased during ATP stress only in ischemic myocardium. This phenomenon disappeared immediately after PCI. Temporal analysis of TAVC-E SR appeared to be useful to assess the regional myocardial ischemia.

Persistence of systolic and diastolic regional dysfunction after brief episodes of myocardial ischemia evaluated with velocity vector imaging

BACKGROUND

The time course and characteristics of persistent regional dysfunction after ischemia remain unclear. Velocity vector imaging (VVI) allows accurate quantification of regional myocardial function. The aim of this study was to characterize the time course of regional diastolic and systolic abnormality after recovery from different durations of ischemia by VVI.

METHODS

72 rats underwent brief left coronary occlusion (3, 5, 10 and 15 min, respectively) followed by reperfusion for 4-8h. Hemodynamic measurements and VVI were performed at various time points. Regional systolic and diastolic functions were estimated from peak diastolic and systolic circumferential strain rate (SR-d and SR-s) of the left ventricle, respectively.

RESULTS

Both SR-d and SR-s were significantly decreased in the ischemic segment during occlusion compared to non-ischemic segment. With the increase in occlusive time, the duration of reduced SR-d and SR-s after reperfusion was prolonged. Both SR-d and SR-s returned to pre-occlusion values in less than 30 min after reperfusion in the 3 min and 5 min ischemia groups. However, in the 10- and 15-min ischemia groups, SR-d did not fully recovered even at 240 min after reperfusion despite complete recovery of SR-s. The left ventricular hemodynamics during occlusion were significantly changed in all groups and returned to baseline immediately after reperfusion.

CONCLUSION

The persistence of diastolic regional dysfunction is longer than systolic regional dysfunction after a relative longer ischemic event, suggesting that recent myocardial ischemic insult mimicking variant angina may be recognized with the evaluation of regional diastolic function.

Impact of diabetes on postinfarction heart failure and left ventricular remodeling

Diabetes mellitus, the metabolic syndrome, and the underlying insulin resistance are increasingly associated with diastolic dysfunction and reduced stress tolerance. The poor prognosis associated with heart failure in patients with diabetes after myocardial infarction is likely attributable to many factors, important among which is the metabolic impact from insulin resistance and hyperglycemia on the regulation of microvascular perfusion and energy generation in the cardiac myocyte. This review summarizes epidemiologic, pathophysiologic, diagnostic, and therapeutic data related to diabetes and heart failure in acute myocardial infarction and discusses novel perceptions and strategies that hold promise for the future and deserve further investigation.

The effect of repeated ischaemic periods on left ventricular dynamics during percutaneous coronary intervention

AIMS

To study online left ventricular (LV) dynamic effects of transmural ischaemia and reperfusion during consecutive balloon coronary occlusions in the setting of percutaneous coronary intervention (PCI).

METHODS AND RESULTS

In 10 consecutive unselected patients with stable angina (seven males, mean age 62 ± 3 years) who underwent elective PCI, LV dynamics were continuously recorded using a pressure-conductance catheter to simultaneously measure pressure and volume (PV-loop). The effects of a prolonged balloon coronary occlusion (148 ± 19 s) and a second occlusion on various LV function parameters were studied, as well as recovery of these parameters after reperfusion. Ischaemia caused an immediate (<5 s) decrease in diastolic function, followed by a decrease in contractile function, indicated by a rightward shift of the PV-loop, and a decreased dP/dtmax and ejection fraction. All parameters recovered within two minutes after reperfusion. The second occlusion caused a more rapid and more pronounced decrease in systolic and global LV function, while the 12-lead ECG showed less ST-segment deviation.

CONCLUSIONS

Online LV pressure-volume measurements during elective PCI show that prolonged balloon coronary occlusion causes a phased ischaemic response of diastolic dysfunction, and then systolic dysfunction with more pronounced deterioration during a consecutive ischaemic period, paradoxical to the ischaemic electrocardiographic signs.

Stunning and cumulative left ventricular dysfunction occurs late after coronary balloon occlusion in humans insights from simultaneous coronary and left ventricular hemodynamic assessment

OBJECTIVES

We aimed to investigate whether left ventricular (LV) stunning could be detected late after coronary occlusion when coronary flow has normalized.

BACKGROUND

Stunning and cumulative LV dysfunction after ischemia reperfusion has been clearly demonstrated in animal models but has been refuted in several angioplasty models in humans. However, these studies have assessed LV function early, during the reactive hyperemic phase, which might have augmented LV function.

METHODS

We recruited 20 male subjects with single-vessel, type A coronary disease, and normal ventricular function. We simultaneously measured LV function with a conductance catheter and coronary flow velocity with a Combowire (Volcano Therapeutics, Inc., Rancho Cordova, California) at baseline (BL), for 30 s after a low-pressure coronary balloon occlusion for 1 min and again after 30 min, before a second balloon occlusion.

RESULTS

Stunning was detected at 30 min after a 1-min balloon occlusion: stroke volume (ml) BL1: 88.4 (22.8) versus BL2: 79.4 (24.0), p = 0.04; tau (ms) BL1: 49.8 (9.0) versus BL2: 52.5 (8.9), p = 0.02, despite full recovery of coronary average peak velocity (p = 0.62). A second balloon occlusion caused cumulative LV dysfunction: stroke volume (ml) BO1: 77.3 (34.6) versus BO2 64.9 (22.9), p = 0.01. Reactive hyperemia significantly augmented early recovery systolic function: dP/dt max 30 s: +5.8% versus 30 min - 5.4%, p = 0.0009.

CONCLUSIONS

Coronary occlusion for 1-min results in late stunning and cumulative LV dysfunction after 30 min. Reactive hyperemia augments stunned LV systolic function in early recovery.

Diastolic dysfunction in diabetes and the metabolic syndrome: promising potential for diagnosis and prognosis

Cardiac disease in diabetes mellitus and in the metabolic syndrome consists of both vascular and myocardial abnormalities. The latter are characterised predominantly by diastolic dysfunction, which has been difficult to evaluate in spite of its prevalence. While traditional Doppler echocardiographic parameters enable only semiquantitative assessment of diastolic function and cannot reliably distinguish perturbations in loading conditions from altered diastolic functions, new technologies enable detailed quantification of global and regional diastolic function. The most readily available technique for the quantification of subclinical diastolic dysfunction is tissue Doppler imaging, which has been integrated into routine contemporary clinical practice, whereas cine magnetic resonance imaging (CMR) remains a promising complementary research tool for investigating the molecular mechanisms of the disease. Diastolic function is reported to vary linearly with age in normal persons, decreasing by 0.16 cm/s each year. Diastolic function in diabetes and the metabolic syndrome is determined by cardiovascular risk factors that alter myocardial stiffness and myocardial energy availability/bioenergetics. The latter is corroborated by the improvement in diastolic function with improvement in metabolic control of diabetes by specific medical therapy or lifestyle modification. Accordingly, diastolic dysfunction reflects the structural and metabolic milieu in the myocardium, and may allow targeted therapeutic interventions to modulate cardiac metabolism to prevent heart failure in insulin resistance and diabetes.

Postischemic infusion of sivelestat sodium hydrate, a selective neutrophil elastase inhibitor, protects against myocardial stunning in swine

PURPOSE

It seems controversial whether or not neutrophil elastase inhibitors are effective in attenuating myocardial ischemia/reperfusion injury. We thus investigated possible protective effects of sivelestat, a neutrophil elastase inhibitor, against myocardial stunning i.e., prolonged myocardial dysfunction following a brief episode of ischemia.

METHODS

Swine were divided into control group (group C), low-dose sivelestat group (group L), and high-dose sivelestat group (group H) (n = 7 for each group). All the swine were subjected to myocardial ischemia through ligation of the left anterior descending (LAD) coronary artery for 12-min, followed by 90-min reperfusion. Sivelestat was infused intracoronally at concentrations of 6 and 60 mg/ml throughout the reperfusion period in groups L and H, respectively, while saline was infused in the group C. Heart rate (HR), left ventricular developed pressure (LVdP), maximum rate of LVdP (LVdP/dt (max)), LV end-diastolic pressure (LVEDP), percentage of segment shortening (%SS, an index of regional myocardial contractility), and coronary venous interleukin-6 concentration in the LAD perfusion area were measured before ischemic induction and during reperfusion.

RESULTS

The ischemia/reperfusion insult did not cause any significant changes in HR, LVdP, LVdP/dt (max), and LVEDP in all groups. However, it significantly reduced %SS in the LAD perfusion area and increased the interleukin-6 concentration in group C. Those changes in %SS and the interleukin-6 concentration were both greatly attenuated, but not prevented, in groups L and H.

CONCLUSION

Sivelestat presumably attenuates myocardial contractile dysfunction due to myocardial stunning by inhibiting neutrophil-derived elastase, thereby suppressing the production of interleukin-6 in activated neutrophils.

Intra-operative myocardial ischaemia cannot be detected by analysis of transmitral inflow patterns in patients undergoing off-pump coronary surgery

BACKGROUND AND OBJECTIVE

Transmitral inflow patterns have been used for detection of myocardial ischaemia. However, its diagnostic value has not been tested in anaesthetized and mechanically ventilated patients undergoing coronary artery bypass graft surgery.

METHODS

Transmitral inflow patterns were studied by transoesophageal Doppler echocardiography in 43 patients undergoing coronary artery bypass graft surgery without cardiopulmonary bypass after opening of the sternum (baseline) and during grafting of the left anterior descending artery. Peak early (E) and peak late (A) transmitral velocities and their ratio (E/A) were recorded. Myocardial ischaemia was defined by standard criteria using two-dimensional echocardiography and seven-lead electrocardiogram.

RESULTS

Thirty-one patients (64 +/- 8 yr, 9 women) fulfilled the predefined inclusion criteria for analysis. During distal revascularization, 16 patients showed myocardial ischaemia and 15 did not. The use of vasoactive drugs, haemodynamic findings and transmitral inflow patterns were similar in both groups at baseline and during grafting. In the ischaemic group, E was 67.1 +/- 13.9 cm s-1 at baseline and 69.5 +/- 23.2 cm s-1 during grafting, and the E/A ratios were 1.3 +/- 0.3 and 1.4 +/- 0.9, respectively. In the non-ischaemic group, E was 64.0 +/- 17.1 cm s-1 at baseline and 60.9 +/- 14.8 cm s-1 during grafting, and the E/A ratios were 1.4 +/- 0.7 and 1.2 +/- 0.3, respectively.

CONCLUSIONS

Analysis of Doppler findings of transmitral inflow patterns did not allow for detection of myocardial ischaemia during surgical revascularization of the myocardium.

Early reperfusion phenomena

Cycles of ischemia-reperfusion are ubiquitous in clinical cardiology. Depending on the duration and intensity of the ischemic episode as well as its repetition mode, several pathophysiologic syndromes have been identified, such as myocardial stunning, hibernation, and preconditioning. It remains a difficult exercise to distinguish ischemic from reperfusion damage. Production of oxygen free radicals and alteration in calcium homeostasis are major players during early reperfusion, responsible for the pathologic and functional alterations. At the molecular level, upregulation and downregulation of a number of genes have been observed in stunned myocardium, pointing toward some inborn survival adaptive mechanism. The no-reflow phenomenon, a most paradoxic event after reperfusion, usually occurs after more prolonged episodes of ischemia. The underlying mechanism involves additional lesions to the microvasculature interacting with myocytes lesions. Further insight into molecular and genomic adaptation to ischemia and reperfusion will undoubtedly help to improve our ability to fight reperfusion injury.

Impaired Diastolic Function After Exchange of Endogenous Troponin I With C-Terminal Truncated Troponin I in Human Cardiac Muscle

The specific and selective proteolysis of cardiac troponin I (cTnI) has been proposed to play a key role in human ischemic myocardial disease, including stunning and acute pressure overload. In this study, the functional implications of cTnI proteolysis were investigated in human cardiac tissue for the first time. The predominant human cTnI degradation product (cTnI 1–192 ) and full-length cTnI were expressed in Escherichia coli , purified, reconstituted with the other cardiac troponin subunits, troponin T and C, and subsequently exchanged into human cardiac myofibrils and permeabilized cardiomyocytes isolated from healthy donor hearts. Maximal isometric force and kinetic parameters were measured in myofibrils, using rapid solution switching, whereas force development was measured in single cardiomyocytes at various calcium concentrations, at sarcomere lengths of 1.9 and 2.2 μm, and after treatment with the catalytic subunit of protein kinase A (PKA) to mimic β-adrenergic stimulation. One-dimensional gel electrophoresis, Western immunoblotting, and 3D imaging revealed that approximately 50% of endogenous cTnI had been homogeneously replaced by cTnI 1–192 in both myofibrils and cardiomyocytes. Maximal tension was not affected, whereas the rates of force activation and redevelopment as well as relaxation kinetics were slowed down. Ca 2+ sensitivity of the contractile apparatus was increased in preparations containing cTnI 1–192 (pCa 50 : 5.73±0.03 versus 5.52±0.03 for cTnI 1–192 and full-length cTnI, respectively). The sarcomere length dependency of force development and the desensitizing effect of PKA were preserved in cTnI 1–192 -exchanged cardiomyocytes. These results indicate that degradation of cTnI in human myocardium may impair diastolic function, whereas systolic function is largely preserved.

The effect of coronary angioplasty on plasma NT-proBNP level in patients with and without arterial hypertension

AIMS

The purpose of the study was to assess the effect of percutaneous transluminal coronary angioplasty (PTCA) on plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) level in hypertensive and normotensive subjects with and without systolic left ventricular dysfunction.

METHODS AND RESULTS

Forty patients affected by ischemic heart disease and submitted to PTCA were studied. The patients were divided into four groups: group I - 10 patients with essential arterial hypertension (HT) and normal left ventricular ejection fraction (EF); group II - 10 patients with HT and EF < 55%; group III - 10 patients without HT and with normal EF; group IV - 10 patients without HT and with EF < 55%. Blood samples were collected twice: 24 h before and after PTCA. The plasma NT-proBNP concentrations increased significantly in group I (368+/-103 pg/ml vs 488 +/- 182 pg/ml; p < 0.05), in group III (257 +/- 107 pg/ml vs 447 +/- 198 pg/ml; p < 0.05), and in group IV (419 +/- 99 pg/ml vs 826 +/- 432 pg/ml; p < 0.05) 24 h after PTCA. There were significant differences in the relative change in plasma NT-proBNP concentrations between groups I and II, and between groups III and IV.

CONCLUSIONS

Successful coronary angioplasty results in a rise in plasma NT-proBNP concentration. The increase is less expressive in patients with systolic left ventricular dysfunction. The presence of hypertension does not affect NT-proBNP concentration after PTCA.

Reduced serine–16 and threonine–17 phospholamban phosphorylation in stunning of conscious dogs

OBJECTIVE

Cardiac stunning is the consequence of a brief cardiac ischemia. The underlying mechanism is not completely understood.

METHODS

Here we induced cardiac transient ischemia in conscious instrumented dogs by means of an occluder in the left anterior descending coronary artery (LAD). Contractile performance, monitored by ultrasound crystals, was reduced during and after ischemia in the LAD area. For control in the same animals cardiac performance was measured in the area of left circumflex coronary artery (Ramus circumflexus, RCx). In the RCx area, no decline in contractility was noted. Tissue was obtained from stunned LAD area and from control areas (RCx).

RESULTS

Phospholamban phosphorylation on both serine-16 and threonine-17 was reduced in LAD areas compared to RCx areas. Reduced phosphorylation of PLB is known to inhibit cardiac contractility. While phosphorylation of PLB was reduced, the activity of the appropriate protein phosphatases and protein kinases was not different between tissue obtained from LAD or RCx areas.

CONCLUSION

Reduced formation of cAMP might underlie the contractile dysfunction in myocardial stunning.

Usefulness of left ventricular diastolic wall motion abnormality as an early predictor of left ventricular dilation after a first acute myocardial infarction

To determine the relation between regional diastolic wall motion abnormality and left ventricular remodeling after acute myocardial infarction (AMI), Doppler echocardiography and color kinesis with assessment of global and regional systolic and diastolic functions were performed in 84 patients who developed AMI within 24 hours of admission. In a multivariate logistic regression analysis, the percentage of left ventricular myocardial segments with diastolic wall motion abnormality (p = 0.008), absence of myocardial viability (p = 0.01), and overall diastolic function (p = 0.001) were predictors of remodeling after AMI.

Diastolic wall motion abnormality after myocardial infarction: relation to neurohormonal activation and prognostic implications

BACKGROUND

Systolic wall motion abnormality (WMA) after acute myocardial infarction (AMI) is a major determinant of outcome; the presence and importance of diastolic WMA after AMI are unknown. We therefore sought to detect diastolic WMA using color kinesis and to assess its relation to neurohormonal activation and its prognostic importance in a consecutive population with a first AMI.

METHODS

Complete color-encoded color kinesis and 2-dimensional and Doppler echocardiography were performed in 149 consecutive patients with documented first AMI within 24 hours of their admission. N-terminal pro-brain natriuretic peptide was measured 3 days after AMI. Study end point was cardiac death or readmission for heart failure.

RESULTS

Diastolic area of WMA exceeded the systolic area in all but 5 patients (97%) and was significantly correlated with brain natriuretic peptide (unadjusted beta = .67, P < .0001; adjusted for systolic function, age, Killip class, and overall diastolic function beta = .27, P = .007). Diastolic WMA was also correlated with the number of diseased vessels on coronary angiography (beta = .59, P < .0001). During follow-up, 25 patients died and 11 were readmitted because of recurrent heart failure. On univariate analysis, the area of diastolic WMA was a predictor of the composite end point (hazard ratio 1.07 [95% CI 1.05-1.09], P < .0001) and remained a predictor on multivariate Cox analysis after adjustment of well-known risk factors, left ventricular systolic and overall diastolic functions (hazard ratio 1.09 [95% CI 1.06-1.15], P < .001).

CONCLUSION

The extent of diastolic WMA can be assessed early after AMI using color kinesis. Diastolic WMA is associated with neurohormonal activation and angiographic severity of coronary artery disease and provides independent prognostic information.

Impaired Coronary Flow Reserve in Hemodialysis Patients: A Transthoracic Doppler Echocardiographic Study

BACKGROUND

Coronary flow reserve (CFR) reflects the functional capacity of microcirculation to adapt to blood demand during increased cardiac work. In this study, CFR of hemodialysis patients with angiographically normal coronary arteries was evaluated using transthoracic second harmonic Doppler echocardiography.

METHODS AND RESULTS

Ten hemodialysis patients, and 14 sex-, age- and left ventricular mass index-matched hypertensive controls with angiographically normal coronary arteries underwent transthoracic second harmonic Doppler echocardiographic examination. Coronary basal diastolic peak flow velocities and hyperemic peak flow velocities after dipyridamole infusion (0.56 mg/kg over 4 min) were measured. CFR was defined as the ratio of hyperemic to basal diastolic peak velocities. CFR > or =2.0 was regarded as normal. Additionally, Doppler tissue imaging pulse wave measurements were taken from the lateral and septal corners of the mitral annulus. CFR values were significantly lower in the study group than in the control group (2.03 +/- 0.3 vs. 2.61 +/- 0.5, p = 0.005). In 5 of 10 hemodialysis patients, CFR was <2.0 (50%), however in only 1 of 14 control patients it was <2.0 (5%).

CONCLUSIONS

Impairment of coronary microvasculature occurs earlier in patients with chronic renal failure and may be the harbinger of subsequent primary uremic myocardial disease. In patients with chronic renal failure and normal coronary arteries, decreased CFR by transthoracic echocardiography might be regarded as an early finding of an affected coronary vasculature.

Effects of Postischemic Regional Left Ventricular Diastolic Wall Motion Abnormalities or Delayed Relaxation Following Coronary Vasospasm on Global Diastolic Function

BACKGROUND

Regional left ventricular (LV) diastolic wall motion abnormalities detected by color kinesis (CK), an echocardiographic technique, may be a more sensitive measure to postischemic damage following coronary spasm than parameters of global diastolic function.

METHODS AND RESULTS

Regional LV diastolic wall motion was evaluated by using CK in 18 patients with variant angina on the day following coronary spasm, which was induced by intracoronary acetylcholine. Fractional regional LV cavity area expansion in the short-axis view during the first 30% of the LV filling time, was used to identify postischemic asynchronous diastolic wall motion. Regional delayed relaxation was observed in any of the LV regions in all the patients, who were divided into 2 groups (Group S: 7 patients with single-vessel spasm with regional delayed relaxation in one area. Group M: 11 patients with multivessel spasm or spasm of the proximal left anterior descending branch with regional delayed relaxation in multiple areas). In Group S, no abnormality (0%) was noted in any of the indexes of global diastolic function including the isovolumic relaxation time, the ratio of peak rapid filling to peak atrial filling velocities and the deceleration time. In contrast, in 5 (45%) of the Group M patients, abnormalities were noted in all of those indexes.

CONCLUSIONS

Postischemic regional LV-delayed relaxation following coronary vasospasm was detected sensitively by analysis of CK images. The indexes of global LV diastolic function are insensitive to postischemic damage following single vessel spasm, although they are somewhat sensitive following multivessel spasm.

Nicardipine or nitroglycerin in patients with failed percutaneous coronary angioplasty: effect on myocardial diastolic function

OBJECTIVE

To evaluate whether intracoronary vasodilators can improve diastolic function in 32 patients with failed percutaneous transluminal coronary angioplasty (PTCA).

DESIGN

Clinical trial.

SETTING

Single-institution, academic hospital.

PARTICIPANTS

Failed PTCA patients undergoing emergency coronary artery bypass grafting surgery.

INTERVENTIONS

Patients were divided into 2 groups: group A received 0.1 mg of intracoronary nicardipine, and group B received 20 microg of intracoronary nitroglycerin. Both drugs were administrated via a coronary dilatation perfusion catheter inserted in the catheterization laboratory by the cardiologist. Subsequently, they were continuously infused via the side port of the introducer of the pulmonary artery catheter and titrated to keep systolic blood pressure at about two thirds of the control value. Transesophageal echocardiography (Power Vision/6000, 9-mm 5MHZ Probe; Toshiba, Elmsford, NY) was used in this study.

MEASUREMENTS AND MAIN RESULTS

Left ventricular ejection fraction, cardiac index, tissue Doppler imaging velocity of the left ventricle and mitral annulus, and troponin levels were measured before and after administration of the 2 vasodilators and after cardiopulmonary bypass. Diastolic dysfunction was found preoperatively in all the patients and responded only to intracoronary nicardipine. Ea of mitral annulus velocity significantly increased in group A patients from 7.5 +/- 0.02 to 11.8 +/- 0.01 (p < 0.005) and decreased in group B patients from 8.0 +/- 0.03 to 7.5 +/- 0.02 after nicardipine or nitroglycerin administration. Left ventricular ejection fraction and cardiac index increased significantly (p < 0.005) only after nicardipine administration. Troponin levels were significantly lower in group A than in group B patients (p < 0.005).

CONCLUSION

Intracoronary nicardipine improves diastolic function and myocardial flow velocity in patients with failed PTCA undergoing emergency coronary artery bypass graft surgery.

Hibernation, Stunning, and Preconditioning: Historical Perspective, Current Concepts, Clinical Applications, and Future Implications

Despite considerable advances, coronary artery disease is the leading cause of morbidity and mortality in the Western world. The development of effective therapeutic strategies for protecting the myocardium from ischemia would have major impact on patients with coronary artery disease. It is now accepted that patients with coronary artery disease can experience prolonged regional ischemic dysfunction that does not necessarily arise from irreversible tissue damage, and to some extent, can be reversed by restoration of blood flow. The initial stages of dysfunction are probably caused by chronic stunning that can be reversed after revascularization, resulting in rapid and complete functional recovery. On the other hand, the more advanced stages of dysfunction likely correspond to chronic hibernation. After revascularization, functional recovery will probably be quite delayed and mostly incomplete. Over the past decade, the possibility that an innate mechanism of myocardial protection might be inducible in the human heart has generated considerable excitement. In the last two decades, there was phenomenal growth in the understanding of the mechanism known as ischemic preconditioning that is responsible for the innate myocardial protection. Continued research and progress in this area may soon lead to the availability of preconditioning-mimetic treatments. The current concepts, mechanisms, and potential clinical applications of myocardial hibernation, stunning, and ischemic preconditioning are reviewed.

Effects of brief ischemia and reperfusion on the myocardium and the role of nitric oxide

Brief myocardial ischemia/reperfusion has complex effects on the myocardium. In the short term the myocardium may be stunned with temporarily reduced contractile function, though this may also be accompanied by the modification and de novo synthesis of proteins that protect the heart against subsequent early or delayed insults. Repeated episodes of non-lethal ischemia, which are common in the clinical setting, combine all of these phenomena and may ultimately result in chronic contractile dysfunction. Nitric oxide is intimately linked to many of these alterations in cellular function and defense. This article examines data predominantly from in vivo large animal studies that relate to these ischemia-induced changes, the evidence for the proposed mechanisms behind both myocardial stunning and preconditioning while concentrating on the role of nitric oxide in these conditions.

Novel mechanisms mediating stunned myocardium

Myocardial stunning is defined as the prolonged contractile dysfunction following an ischemic episode that does not result in necrosis, which also occurs in patients with coronary artery disease. There is also evidence to consider myocardial stunning as a fundamental component of hibernating myocardium. Various experimental approaches (from a brief episode to prolonged partial ischemia) and animal models (from rodents to large mammals) have been developed to investigate the pathogenesis of myocardial stunning. Three hypotheses to explain the mechanism, i.e. oxygen radical, Troponin I degradation, and Ca(2+), have been proposed. The first was tested primarily using large mammalian models, whereas the others were tested primarily using rodent models. Recently, the Ca(2+) handling hyothesis has been tested in a large mammalian swine model of myocardial stunning, in which both Ca(2+) and transients and L-type Ca(2+) current density were decreased. Relaxation function and phospholamban phosphorylation are also radically different in large mammalian and rodent models. In addition, troponin I degradation, which was identified as the mechanism of stunning in rodent models, was not found in stunned swine myocardium. Interestingly, the large mammalian model demonstrates that stunning elicits broad changes in gene and protein regulation, some of which have not been observed in the heart previously. The overall genomic adaptation upregulates the expression of survival genes that prevent irreversible damage. Pursuing these new concepts derived from large mammalian models of ischemia/reperfusion will provide more comprehensive mechanistic information underlying myocardial stunning and will serve to devise new therapeutic modalities for patients.

Myocardial stunning in man

Myocardial stunning refers to the contractile dysfunction that occurs following an episode of acute ischaemia, despite the return of normal blood flow. The phenomenon was initially identified in animal models, where it has been very well characterised, and there was initial doubt about whether a similar syndrome occurred in humans, and if it did, whether it was of any clinical relevance. This article outlines the conditions that must be met to diagnose myocardial stunning and why it has been difficult to confirm its presence in humans. The clinical scenarios where it has now been clearly identified and those others where it may also occur and be of clinical importance are also reviewed.

Evidence that stunning can be cumulative in man

Myocardial stunning and hibernation are two entities that have become increasingly recognised as clinically important causes of reversible left ventricular (LV) dysfunction. Their occurrence is important as resting myocardial dysfunction, which was once thought to be irreversible, may recover if ischaemia is lessened or abolished. Recent evidence has suggested that cumulative stunning can occur in man and may in fact be responsible for the phenomenon of hibernation. In this chapter we will review the evidence supporting the occurrence of cumulative stunning in man.

Prolonged diastolic dysfunction following exercise induced ischaemia: a gated myocardial perfusion SPECT study

Prolonged impairment of left ventricular (LV) systolic function following exercise induced ischaemia has been well demonstrated. The objective of this study was to examine the effect of exercise induced ischaemia on the post-stress LV diastolic function in patients with coronary artery disease (CAD). Seventy-four subjects with known or suspected CAD underwent gated myocardial single photon emission computed tomography (SPECT) 1 h after administration of 99mTc tetrofosmin according to a standard same day exercise rest protocol. LV volumes and ejection fractions (LVEFs) were determined by the Cedars-Sinai program. Fourier transformation of the gated SPECT volume curve was performed retaining the fourth order harmonics, and peak filling rate (PFR) and time-to-PFR (TPFR) were calculated from the derivative curve. In patients with exercise induced ischaemia (n =26), 1 h post-stress PFR (2.66+/-0.75 s(-1)) and TPFR (119+/-12 ms) were significantly impaired in comparison to the resting PFR (3.06+/-0.74 s; P=0.0002) and TPFR (114+/-10 ms; P=0.03), respectively. In normal subjects (n =26) and in patients with infarction (n =22), the post-stress indices were similar to the resting values. When reduction of PFR or LVEF greater than the variability (2SD) of differences between the post-stress and resting values in the normal group was defined as significant impairment, six of the 26 ischaemic patients (23%) had such changes in PFR. All these patients exhibited severe ischaemia and five of them had simultaneous systolic impairment. Only one (4%) of the normal subjects and none of the patients in the infarction group showed such impairments. Stepwise logistic regression analysis of stress, scan and coronary variables revealed that the summed reversibility score, a scintigraphic index of ischaemic severity, was the only determinant of post-stress changes in LVEF and PFR. In conclusion, exercise induced LV diastolic impairment persists for a prolonged period after resolution of the ischaemic episode. The incidence and magnitude of the diastolic impairment are determined by the severity of the exercise provoked ischaemia.

Coronary flow reserve and myocardial diastolic dysfunction in arterial hypertension

The aim of this study was to assess the relation between coronary blood flow and left ventricular (LV) myocardial diastolic dysfunction in arterial hypertension. The study population included 30 hypertensive patients who were free of coronary artery disease and pharmacologic therapies. They underwent standard Doppler echocardiography and color tissue Doppler of the middle posterior septum at baseline and with high-dose dobutamine, and second-harmonic Doppler flow analysis of the distal left anterior descending coronary artery at baseline and after vasodilation by dipyridamole (0.56 mg/kg IV in 4'). Coronary flow reserve (CFR) was estimated as the ratio of hyperemic and baseline diastolic flow velocities. According to CFR, hypertensives were divided into 2 groups: 15 patients with normal CFR (>/=2) and 15 patients with reduced CFR (<2). The 2 groups were comparable for sex, age, body mass index, baseline heart rate, and blood pressure. LV mass index was greater in hypertensives with reduced CFR (p <0.01). By color tissue Doppler, baseline and high-dose dobutamine septal systolic velocities did not differ between the 2 groups. The ratio between myocardial velocities in early diastole and at atrial contraction (E(m)/A(m) ratio) was lower in patients with reduced CFR, both at baseline (p <0.05) and with high-dose dobutamine (p <0.00001). After adjusting for age, body mass index, LV mass index, and both high-dose dobutamine diastolic blood rate and heart rate by a multiple linear regression analysis, E(m)/A(m) ratio at high-dose dobutamine was independently associated with CFR in the overall population (beta 0.62, p <0.0005) (cumulative R(2) 0.38, p <0.0005). In conclusion, this study provides evidence of an independent association between CFR and myocardial diastolic function. In hypertensive patients without coronary artery stenosis, CFR alteration may be a determinant of myocardial diastolic dysfunction or diastolic impairment that should be taken into account as possibly contributing to coronary flow reduction.

Acute left ventricular failure after transcatheter closure of a secundum atrial septal defect in a patient with coronary artery disease: a critical reappraisal

We report a case of acute left ventricular failure after transcatheter closure of a single secundum atrial septal defect in a 68-year-old man with coronary artery disease. Just before the procedure, two coronary lesions had been treated with direct stenting. Transcatheter closure of atrial septal defects should always be deferred in ischemic heart disease patients who need percutaneous myocardial revascularization.