Regional Left Ventricular Systolic Dysfunction Research Articles

TAKOTSUBO SYNDROME

Takotsubo syndrome, also known as Takotsubo cardiomyopathy, stress-induced cardiomyopathy, transient apical ballooning and broken heart syndrome, is a disease characterized by transient regional left ventricular systolic dysfunction. It is usually determined by emotional or physical stress. Even though it was thought to be a self-limiting condition, Takotsubo syndrome is now known to be associated with important short and long-term morbidity and mortality. Takotsubo syndrome affects 2-3% of all patients and 5-6% of female patients presenting with acute coronary syndrome (frequently women in the sixth decade). The Takotsubo syndrome cases are mostly preceded by acute emotional or physical triggers such as: family death, financial loss, anxiety, excessive work, domestic abuse, anxiety, fear for medical procedures, severe pain, sepsis, post surgeries, and cancer. Diagnosis of Takotsubo syndrome can sometimes be difficult due to clinical manifestations similar to acute myocardial infarction. Myocardial necrosis biomarkers (Troponin I, Troponin T and Creatinin kinase) are elevated, with values comparable to those in patients with acute myocardial infarction. Transthoracic echocardiography usually shows akinetic or dyskinetic apical and mid-ventricular segments of the left ventricle compared to the hyperkinetic basal segments (“apical ballooning” aspect) and left ventricle systolic dysfunction. The positive diagnosis of Takotsubo syndrome is made on coronary angiography, normal or non-obstructive coronary artery disease

Reverse Takotsubo Cardiomyopathy in a Patient With Commotio Cordis

Takotsubo cardiomyopathy (TCM), also known as stress cardiomyopathy or “broken heart syndrome”, is characterized by acute transient regional left ventricular systolic dysfunction in the absence of obstructive coronary artery disease or acute plaque rupture. Atypical forms and rare anatomical variants can have different presentations; hence, recognition becomes more important. Prognosis is much more favorable if managed appropriately. An equally infrequent cause of cardiac arrest is commotio cordis (CC). This is defined as sudden cardiac death secondary to a blunt chest wall impact leading to ventricular arrhythmias. We report a case with findings of TCM and/or CC in a patient with a blunt chest trauma in the setting of motor vehicle accident.

TAKOTSUBO CARDIOMYOPATHY SECONDARY TO ACUTE BACTERIAL MENINGITIS

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Infection and sepsis are not uncommon causes of cardiomyopathy due to a decrease in ventricular function. Cardiovascular dysfunction in sepsis can be seen as septic cardiomyopathy, Takotsubo cardiomyopathy, refractory shock or myocardial injury. A study showed that Takotsubo cardiomyopathy was present in 0.15% of admissions with severe sepsis. It should be considered in the differential diagnosis of acute coronary syndrome especially post-menopausal women with preceding stressful events. We present a case of bacterial meningitis leading to Takotsubo’s cardiomyopathy in the setting of CSF leak. CASE PRESENTATION: A 67-year-old woman with no past medical history presented to the emergency department with diarrhea, vomiting, and confusion. On arrival, she was hypotensive to 87/66mmHg, tachycardic 116bpm and hypoxic to 83% on room air. Laboratory evaluation was significant for leukocytosis of 29.2 k/ul, troponin 5.02 ng/ml, lactic acid 2.9 mmol/l, BNP 788 pg/ml. Cerebrospinal fluid showed a white blood cell count of 5011 (91% neutrophils), protein 791 mg/dl, glucose 95 mg/dl. She was admitted with a diagnosis of an NSTEMI, acute meningeal encephalitis and treated with aztreonam, vancomycin, doxycycline, and dexamethasone. Cultures revealed streptococcus viridians and treatment was narrowed to ceftriaxone. Facial CT showed a possible area of dehiscence concern for possible CSF leak. No significant coronary artery disease on the angiogram Echocardiogram was consistent with Takotsubo cardiomyopathy. The patient's cardiomyopathy was treated with goal-directed medical therapy with complete resolution of symptoms. DISCUSSION: Takotsubo cardiomyopathy is defined as a transient regional left ventricular systolic dysfunction without obstructive coronary artery disease and usually triggered by emotional or physical stress. During sepsis, there is an activation of the sympathoadrenergic system with rapid elevation in circulating catecholamine levels. Pathogenesis is related to myocardial stunning, catecholamine toxicity, impaired myocyte metabolism. According to Mayo Clinic criteria there should be: 1) transient hypokinetic, akinesias or dyskinesia of the LV midsegments, 2) absence of CAD, 3) EKG abnormalities or troponin elevation, 4) absence of pheochromocytoma or myocarditis. Patients can present with mild to moderate congestive heart failure or hypotension due to a reduction in stroke volume. The mean age of presentation ranges from around 60 to 75 years. The prognosis is excellent, mortality from 0%-8% and a recurrence occurs in <10% of patients. The treatment is based on the management of the underlying etiology and supportive cardiovascular care. CONCLUSIONS: Patients with suspected TTC need to be work up to rule out ACS with coronary angiogram. Takotsubo’s cardiomyopathy has a good prognosis with recovery on the EF and cardiac function once infection or physical stress disappears. Reference #1: De Giorgi, A., Fabbian, F., Pala, M., Parisi, C., Misurati, E., Molino, C., et al. (2015). Takotsubo Cardiomyopathy and Acute Infectious Diseases: A Mini-Review of Case Reports. Angiology, 66(3), 257–261. Reference #2: Pilgrim, TM, Wyss, TR. Takotsubo cardiomyopathy or transient left ventricular apical ballooning syndrome: a systematic review. Int J Cardiol. 2008;124(3):283–292. Reference #3: Prasad, A, Lerman, A, Rihal, CS. Apical ballooning syndrome (tako-tsubo or stress cardiomyopathy): a mimic of acute myocardial infarction. Am Heart J. 2008;155(3):408–417. DISCLOSURES: No relevant relationships by Daniel Colon Hidalgo, source=Web Response No relevant relationships by Diana Estefania Espinoza Barrera, source=Web Response No relevant relationships by Hugues Orozco, source=Web Response No relevant relationships by Jose Zabala-Genovez, source=Web Response

Takotsubo Cardiomyopathy Following Liver Transplantation: A Report of 2 Cases

PurposeTakotsubo cardiomyopathy, also called apical ballooning syndrome, is characterized by regional left ventricular systolic dysfunction that resembles myocardial infarction in its initial presentation; however, it lacks angiographic evidence of coronary artery disease. We evaluated the incidence of takotsubo cardiomyopathy following liver transplant at a diverse urban transplant program. MethodsThis is a retrospective review of patients transplanted at a single center between 2017 and 2019. Here we report 2 cases of takotsubo cardiomyopathy that developed after liver transplantation. ResultsA 65-year-old woman diagnosed with alcoholic cirrhosis underwent a brain-dead donor liver transplant. The postoperative course was complicated by stroke, pulmonary hypertension, and a left internal jugular thrombus. Six months following transplant, the patient developed takotsubo cardiomyopathy with congestive hepatopathy and died of heart failure complications despite maximal medical care. The second case was a 65-year-old woman with alcoholic cirrhosis admitted for a living donor liver transplant. The postoperative period involved recurrent seizures and elevated troponins with markedly reduced ejection fraction, which were appropriately managed. The patient recovered well with supportive care and was discharged to a rehabilitation facility shortly after. ConclusionWe present a series of patients with takotsubo cardiomyopathy after liver transplantation. The diagnosis depends on the clinical presentation and findings on electrocardiography, echocardiography, and cardiac enzymes. Our patients met the Mayo Clinic diagnostic criteria and were appropriately managed according to guidelines. Our report highlights the possibility of pulmonary hypertension contributing to the development of takotsubo cardiomyopathy. Additional studies are needed to establish a definite correlation.

Fragmented QRS as an early predictor of left ventricular systolic dysfunction in healthy individuals: a nested case-control study in the era of speckle tracking echocardiography

BackgroundSeveral studies addressed the association between fragmented QRS (fQRS) on 12-lead EKG and left ventricular (LV) dysfunction in patients with a variety of cardiovascular disorders. We tested such association in healthy individuals.MethodsOut of 500 healthy participants without -overt cardiovascular disease from the Shiraz Heart Study cohort, we identified 20 subjects with fQRS (cases) and 20 peers without fQRS (controls). Global LV longitudinal strain (GLS) was measured by speckle tracking echocardiography in the two groups. Comparison was made between case and control groups by using chi-square or independent sample t-test or ANOVA.ResultsAge, gender, ejection fraction, LV volume and dimensions did not differ between the case and the control groups. Overall, 14 subjects out of 40 had reduced GLS (≤20%) and 10 of them (25%) had fQRS. GLS was significantly lower in the group with fQRS than in the control group (19.9 ± 1.8 vs 21.4 ± 1.6; p = 0.009).ConclusionsHealthy subjects with fQRS present regional LV systolic dysfunction, assessed by GLS, in the presence of a normal ejection fraction. These data suggest that fQRS may be a promising tool to identify apparently healthy subjects with regional LV systolic dysfunction.

A Percutaneous Solution for Treatment of a Large, Ischaemic Ventricular Septal Defect Presenting with Cardiogenic Shock

Introduction: A 73-year-old man presented to a peripheral hospital with anginal chest pain and anterolateral ST elevation on electrocardiogram and underwent percutaneous intervention to an occluded left anterior descending artery. He had a history of medically managed proximal right coronary artery occlusion. Post–percutaneous intervention auscultation revealed a new pan-systolic murmur at the left sternal edge. Transthoracic echocardiography (TTE) revealed severe, regional left ventricular systolic dysfunction (ejection fraction 32%) and a 0.9-cm ventricular septal defect (VSD). He subsequently developed ventricular arrhythmias and acute renal failure. Repeat TTE showed increasing VSD size (2.0 cm), left–right shunting, and a 38-mmHg pressure gradient.

Echocardiographic assessment of cardiac dysfunction in maintenance hemodialysis patients

Background and Objectives: The hemodialysis (HD) procedure may acutely induce regional left ventricular systolic dysfunction. This study evaluated the echocardiographic parameters in patients with End Stage Renal Disease (ESRD) on HD and to correlate those with clinical findings, more specifically to see whether there is any change in ejection fraction (EF) by developing new regional wall motion abnormality (RWMA) after hemodialysis, and to correlate these changes with the symptoms &amp; hemodynamic condition of the patients.Methodology: This prospective observational study was carried on a total of 100 adult ambulant patients with end stage renal disease (ESRD) on maintenance hemodialysis in the department of Hemodialysis, BIRDEM General Hospital, Shahbag, Dhaka. Their echocardiogram was done 30 min before and after the hemodialysis.Result: It was revealed that majority of the patients were above 60 years (39%), and male to female ratio of about 3:2. The study subjects had diabetes mellitus (79%), hypertension (96%), dyslipidemia (42%), and family history of ischemic heart disease (24%). Chest pain and breathlessness were present in 31% and 42% subjects respectively before hemodialysis. Palpitation (23%), dizziness (19%), oedema (43%) and raised JVP (15%) were seen in the study subjects. Mean (±SD) serum creatinine level was 9.38 (±2.22) mg/dl and hemoglobin level was 9.0 (±1.08) g/dl. Ejection fraction (EF) before hemodialysis were ?55, 40-54 &amp; 30-39 in 62%, 34% and 4% study subjects respectively and after hemodialysis it was ?55, 40-54 &amp; 30-39 in 44%, 46% and 10% study subjects respectively. After HD, left ventricular failure (LVF) occurred in 32% subjects. HD-induced regional left ventricular systolic dysfunction occurred in total 36 patients (36%) and total 14 (14%) patients developed LVF 30 minutes after dialysis. Patients with hemodialysis-induced left ventricular systolic dysfunction were more in those who had worse predialysis EF. Blood pressure, heart rate, chest pain, palpitation, raised Jugular Venous Pressure (JVP) and edema did not differ significantly before and after hemodialysis. Simple regression analysis revealed that the hemodialysis procedure significantly (P&lt;0.05) induce regional left ventricular systolic dysfunction.Conclusions: HD acutely induces regional wall motion abnormalities in a significant proportion of patients. It occurs within 30 min after hemodialysis and is not related to changes in blood pressure, heart rate, JVP and oedema.Bangladesh Crit Care J September 2017; 5(2): 97-100

Hemodialysis-induced regional left ventricular systolic dysfunction.

Introduction Hemodialysis (HD) patients are under observably elevated cardiovascular mortality. Cardiac dysfunction is closely related to death caused by cardiovascular diseases (CVD). In the general population, repetitive myocardial ischemia induced left ventricular (LV) dysfunction may progress to irreversible loss of contraction step by step, and finally lead to cardiac death. In HD patients, to remove water and solute accumulated from 48 or 72 hours of interdialysis period in a 4-hour HD session will induce myocardial ischemia. In this study, we evaluated the prevalence and potential risk factors associated with HD-induced LV systolic dysfunction and provide some evidences for clinical strategies. Methods We recruited 31 standard HD patients for this study from Fudan University Zhongshan hospital. Echocardiography was performed predialysis, at peak stress during HD (15 minutes prior to the end of dialysis), and 30 minutes after HD. Auto functional imaging (AFI) was used to assess the incidence and persistence of HD-induced regional wall motion abnormalities (RWMAs). Blood samples were drawn to measure biochemical variables. Findings Among totally 527 segments of 31 patients, 93.54% (29/31) patients and 51.40% (276/527) segments were diagnosed as RWMAs. Higher cTnT (0.060 ± 0.030 vs. 0.048 ± 0.015 ng/mL, P = 0.023), phosphate (2.07 ± 0.50 vs. 1.49 ± 0.96 mmol/L, P = 0.001), UFR (11.00 ± 3.89 vs. 8.30 ± 2.66 mL/Kg/h, P = 0.039) and lower albumin (37.83 ± 4.48 vs. 38.38 ± 2.53 g/L, P = 0.050) were found in patients with severe RWMAs (RWMAs in more than 50% segments). After univariate and multivariate analysis, interdialytic weight gain (IDWG) was found as independent risk factor of severe RWMAs (OR = 1.047, 95%CI 1.155-4.732, P = 0.038). Discussion LV systolic dysfunction induced by HD is prevalent in conventional HD patients and should be paid attention to. Patients would benefit from better weight control during interdialytic period to reduce ultrafiltration rate.

Relation of Delayed Recovery of Myocardial Function After Takotsubo Cardiomyopathy to Subsequent Quality of Life

Takotsubo cardiomyopathy (TTC) has generally been regarded as a relatively transient disorder, characterized by reversible regional left ventricular systolic dysfunction. However, most patients with TTC experience prolonged lassitude or dyspnea after acute attacks. Although this might reflect continued emotional stress, myocardial inflammation and accentuated brain-type natriuretic peptide (BNP) release persist for at least 3 months. We therefore tested the hypotheses that this continued inflammation is associated with (1) persistent contractile dysfunction and (2) consequent impairment of quality of life. Echocardiographic parameters (global longitudinal strain [GLS], longitudinal strain rate [LSR], and peak apical twist [AT]) were compared acutely and after 3 months in 36 female patients with TTC and 19 age-matched female controls. Furthermore, correlations were sought between putative functional anomalies, inflammatory markers (T2 score on cardiovascular magnetic resonance, plasma NT-proBNP, and high-sensitivity C-reactive protein levels), and the physical composite component of SF36 score (SF36-PCS). In TTC cases, left ventricular ejection fraction returned to normal within 3 months. GLS, LSR, and AT improved significantly over 3-month recovery, but GLS remained reduced compared to controls even at follow-up (-17.9 ± 3.1% vs -20.0 ± 1.8%, p = 0.003). Impaired GLS at 3 months was associated with both persistent NT-proBNP elevation (p = 0.03) and reduced SF36-PCS at ≥3 months (p = 0.04). In conclusion, despite normalization of left ventricular ejection fraction, GLS remains impaired for at least 3 months, possibly as a result of residual myocardial inflammation. Furthermore, perception of impaired physical exercise capacity ≥3 months after TTC may be explained by persistent myocardial dysfunction.

Hemodialysis-Induced Regional Left Ventricular Systolic Dysfunction and Inflammation: A Cross-sectional Study

Hemodialysis may acutely induce regional left ventricular (LV) systolic dysfunction, which is associated with increased mortality and progressive heart failure. We tested the hypothesis that hemodialysis-induced regional LV systolic dysfunction is associated with inflammation and endothelial injury. Additionally, we studied whether hemodialysis-induced LV systolic dysfunction is associated with an exaggerated bioincompatibility reaction to hemodialysis. Cross-sectional study. 105 hemodialysis patients on a thrice-weekly dialysis schedule were studied between March 2009 and March2010. Plasma indexes of inflammation (high-sensitivity C-reactive protein, pentraxin 3 [PTX3], interleukin 6 [IL-6], and IL-6:IL-10 ratio), bioincompatibility (leukocytes, neutrophils, complement C3, and myeloperoxidase), and endothelial function (soluble intercellular adhesion molecule 1 [ICAM-1], von Willebrand factor, proendothelin, and endothelin) were measured just before dialysis and at 60, 180, and 240 minutes intradialysis. Hemodialysis-induced regional LV systolic function. Wall motion score was measured by echocardiography at 30 minutes predialysis, 60 and 180 minutes intradialysis, and 30 minutes postdialysis. We defined hemodialysis-induced regional LV systolic dysfunction as an increase in wall motion score in 2 or more segments. Patients with hemodialysis-induced regional LV systolic dysfunction (n=29 [27%]) had significantly higher predialysis high-sensitivity C-reactive protein, PTX3, IL-6, and lL-6:IL-10 ratio values. Predialysis levels of bioincompatibility and endothelial markers did not differ between groups. Intradialysis courses of markers of inflammation, bioincompatibility, and endothelial function did not differ in patients with versus without hemodialysis-induced regional LV systolic dysfunction. Coronary angiography or computed tomography for quantification of coronary calcifications in our patients was not performed; therefore, we could not relate markers of inflammation to the extent of atherosclerosis. Patients with hemodialysis-induced regional LV systolic dysfunction have a proinflammatory cytokine profile. There was no indication of an association with an exaggerated bioincompatibility reaction to hemodialysis.

Hemodialysis-Induced Regional Left Ventricular Systolic Dysfunction

The hemodialysis procedure may acutely induce regional left ventricular systolic dysfunction. This study evaluated the prevalence, time course, and associated patient- and dialysis-related factors of this entity and its association with outcome. Hemodialysis patients (105) on a three times per week dialysis schedule were studied between March of 2009 and March of 2010. Echocardiography was performed before dialysis, at 60 and 180 minutes intradialysis, and at 30 minutes postdialysis. Hemodialysis-induced regional left ventricular systolic dysfunction was defined as an increase in wall motion score in more than or equal to two segments. Hemodialysis-induced regional left ventricular systolic dysfunction occurred in 29 (27%) patients; 17 patients developed regional left ventricular systolic dysfunction 60 minutes after onset of dialysis. Patients with hemodialysis-induced left ventricular systolic dysfunction were more often male, had higher left ventricular mass index, and had worse predialysis left ventricular systolic function (left ventricular ejection fraction). The course of blood volume, BP, heart rate, electrolytes, and acid-base parameters during dialysis did not differ significantly between the two groups. Patients with hemodialysis-induced regional left ventricular systolic dysfunction had a significantly higher mortality after correction for age, sex, dialysis vintage, diabetes, cardiovascular history, ultrafiltration volume, left ventricular mass index, and predialysis wall motion score index. Hemodialysis induces regional wall motion abnormalities in a significant proportion of patients, and these changes are independently associated with increased mortality. Hemodialysis-induced regional left ventricular systolic dysfunction occurs early during hemodialysis and is not related to changes in blood volume, electrolytes, and acid-base parameters.

Hypertrophic Obstructive Cardiomyopathy Masked by Tako-Tsubo Syndrome: A Case Report

Introduction. Left ventricular outflow obstruction might be part of the pathophysiological mechanism of Tako-tsubo cardiomyopathy. This obstruction can be masked by Tako-tsubo cardiomyopathy and diagnosed only by followup. Case Presentation. A 70-year-old female presented with Tako-tsubo cardiomyopathy and masked obstructive hypertrophic cardiomyopathy at presentation. Conclusion. Tako-tsubo cardiomyopathy typically presents like an acute MI and is characterized by severe, but transient, regional left ventricular systolic dysfunction. Prompt evaluation of the coronary status is, therefore, mandatory. The prognosis under medical treatment of heart failure symptoms and watchful waiting is favourable. Previous studies showed that LVOT obstruction might be part of the pathophysiological mechanism of TCM. This paper supports this theory. However, TCM may also mask any preexisting LVOT obstruction.

Detection of prolonged regional myocardial systolic dysfunction after exercise-induced myocardial ischemia by strain echocardiography with high frame rate tissue Doppler echocardiography.

Strain echocardiography has enabled quantification of regional myocardial systolic function objectively and is less influenced by tethering effects and cardiac translational artifact than Doppler tissue imaging. Although strain echocardiography has been applied for the detection of inducible ischemia during dobutamine stress, it has not been fully applied to exercise stress echocardiography (ESE) because of technical difficulties. Prolonged myocardial systolic dysfunction after exercise-induced ischemia has been shown previously. Thus, we designed this study to evaluate whether the myocardial strain analysis can detect myocardial ischemia by the assessment of prolonged regional left ventricular (LV) dysfunction in ESE. We performed ESE with myocardial strain imaging system in 20 consecutive patients who had exercise Tl-201 single photon emission computed tomography (SPECT). Myocardial strain curves were obtained at six segments in mid LV walls from the apical approach before and 5min after ESE. We measured the duration from the R wave in the electrocardiogram to the timing of peak systolic strain corrected by the square root of the RR interval (TPSc). We finally calculated the differences of TPSc (ΔTPSc) before ESE and 5min after ESE. The results were compared with SPECT as a reference standard. A receiver operating characteristic curve demonstrated that a ΔTPSc cutoff value of 70ms had a sensitivity of 80% and a specificity of 84% for the detection of myocardial ischemia. Prolonged regional LV systolic dysfunction assessed by ESE with strain analysis was useful for the detection of myocardial ischemia.

Longitudinal, radial and circumferential 2-dimensional strain for quantitative analysis of regional left ventricular systolic dysfunction in patients with coronary artery disease

Objective To assess longitudinal, radial and circumferential systolic strain of regional myocardium in patients with coronary artery disease by 2-dimensional strain echocardiography, and to explore stenosis of coronary artery impacting on regional left ventricular systolic dysfunction in quietscent condition. Methods Twenty-six patients with coronary artery disease were entrolled into this study and 26 healthy volenteers in the control group. The two-dimensional loop-einec were obtained in apical 4-chamber view,apical 2-chamber view and long axis view of left venricular, and three levels of the short axis views (mitral valve,papillary muscle and cardiac apex). According to left ventricle 18 segments divla, there were 194 affected myocardiums in 26 cases. According to stenosis degrees of coronary artery, the affected myocardiums were divided into two groups: group A (coronary stenosis degree≤70%) and group B (coronary stenosis degree>70%). Longitudinal, radial and circumferential systolic strain (SL, SR, SC) from regional myocardium were analyzed. Results Group A had 90 segments. Compared with control group,SL was decreased significantly from control group (P 0.05). Group B had 104 segments. Compared with control group, SL, SC and SR were decreased significantly in group B(P <0.05). There were significant differences in SL,SC and SR between group A and group B(P<0.05). Conclusions Systolic dysfunction of left ventrieular regional myocardium in patients with coronary artery disease could be accuratly analyzed by 2-dimensional strain echocardiography. Changes of SL,SC and SR of regional myoeardium could reflect coronary stenosis severity degree. Key words: Echoardiography; Coronary disease; Ventricular function, left; Two-dimensional strain

Influence of Anterior Mitral Leaflet Second-Order Chordae Tendineae on Left Ventricular Systolic Function

The contribution of anterior mitral leaflet second-order ("strut") chordae tendineae to left ventricular (LV) systolic mechanics is debated; we measured the in vivo contribution of anterior chordae tendineae (ACT) and posterior chordae tendineae (PCT) to regional and global LV contractile function. Eight sheep had radiopaque markers implanted in the LV epicardium, partitioning the ventricle into 12 regions. Microminiature force transducers and snares were sutured to anterior leaflet "strut" chordae originating from ACT and PCT papillary muscles. Chordal tension, marker images, and hemodynamic data were acquired before and after (CUT) severing ACT and PCT. Fractional area shrinkage and slope of the regional end-diastolic area-regional stroke work relation (r-PRSW) were computed for each LV region. CUT did not affect global LV systolic function but reduced FAS in LV segments near the PCT insertion site: equatorial posterior lateral (19+/-2% versus 16+/-2%, P<0.05), apical posterior lateral (23+/-4% versus 19+/-4%, P<0.05), and posterior medial LV segments (16+/-2% versus 13+/-2%, P<0.05). r-PRSW fell near both the ACT (equatorial anterior medial [84+/-8 versus 62+/-11 mm Hg, P<0.05] and lateral [73+/-7 versus 53+/-9 mm Hg, P<0.05]) and PCT (apical posterior medial [91+/-12 versus 67+/-17 mm Hg, P<0.05] and lateral [72+/-8 versus 59+/-9 mm Hg, P<0.05]) LV insertion sites. Maximum tension in PCT was higher than in ACT (0.81+/-0.1 versus 0.52+/-0.08N, P<0.01). Dividing anterior leaflet strut chordae in sheep was associated acutely with regional LV systolic dysfunction near the chordal insertion sites. Caution is necessary when embarking on procedures that cut second-order chordae to treat ischemic mitral regurgitation, since this may compromise LV systolic function in ventricles that are already impaired.

Is There a Long-Term Predictive Value of Intraoperative Low-Dose Dobutamine Echocardiography in Patients Who Have Coronary Artery Bypass Graft Surgery with Cardiopulmonary Bypass?

In patients with coronary artery disease, chronic regional left ventricular systolic dysfunction at rest may be caused by hibernating or by infarcted myocardium. Intraoperative low-dose dobutamine (LDD) echocardiography reliably predicts the immediate recovery of regional myocardial function after coronary artery bypass graft (CABG) surgery. We sought to determine whether intraoperative LDD echocardiography would also predict recovery of regional function after 1 yr. Twenty-five patients with coronary artery disease who underwent CABG surgery with intraoperative LDD echocardiography were evaluated 1 yr later with a follow-up transthoracic echocardiogram. The covariates of left ventricular ejection fraction, old myocardial infarction, and diabetes mellitus were considered in an analysis of regional wall motion (RWM). A 16-segment model and a 1–5-point scoring system were used to evaluate 350 myocardial segments. Multiple logistic regression analysis was performed to determine whether response to intraoperative LDD echocardiography (5 μg · kg−1 · min−1) predicted changes in regional function at 1 yr. A segment was defined as stunned if the RWM score obtained during LDD infusion deteriorated after cardiopulmonary bypass but recovered in the 1-yr follow-up echocardiogram. A response to intraoperative LDD predicted changes in regional function at 1 yr. The overall odds of improvement in regional function were 2.22 times greater (95% confidence interval = 1.29, 3.82;P = 0.0039) with a positive response to intraoperative LDD. The positive predictive value of intraoperative LDD echocardiography for improvement in myocardial function was 0.81 and the negative predictive value was 0.34. The predictive values did not vary with the examined covariates. Of segments with unexpected deterioration of RWM immediately after cardiopulmonary bypass, 87% recovered at the time of the 1-yr follow-up echocardiogram. Contractile reserve demonstrated by intraoperative LDD echocardiography predicts regional function at 1 yr; however, the test cannot predict which segment will not recover. Most of unexpected regional ventricular systolic dysfunction immediately after CABG surgery can be attributed to myocardial stunning.

Gender Differences in Postinfarction Left Ventricular Remodeling

Objective: Previous studies suggest that gender affects the adaptive responses of the heart to some forms of cardiac overload. It is unknown whether gender influences left ventricular (LV) remodeling after myocardial infarction (MI). Methods: We performed transthoracic echocardiographic-Doppler examinations in age-matched male (n = 17) and female (n = 16) rats before, and 1 and 6 weeks after transmural MI or sham surgery. Results: Following large MI (male = 45 ± 1% LV circumference vs. female = 48 ± 4%, p = NS), both male and female rats developed progressive LV dilatation. Infarctions caused a similar degree of global and regional LV systolic dysfunction in males and females. Male rats had significant increases in the thickness of the noninfarcted posterior wall by 6 weeks after MI. However, posterior wall thickness did not change in the infarcted female rats. Average myocyte diameter in the noninfarcted region of the heart was also greater in male than female MI rats. The combination of increased cavity size with little change in wall thickness resulted in a greater decline in relative wall thickness in the female rats compared to the males. Male rats with MI showed progressively restricted LV diastolic filling as assessed by transmitral Doppler recordings. Female rats had less of an increase in the ratio of early to late transmitral velocities and less of an increase in the E wave deceleration rate after MI. Conclusions: Female rats showed a different pattern of LV remodeling than males with less of an increase in thickness of the noninfarcted portions of the left ventricle than males, but comparable LV cavity enlargement and systolic dysfunction. Despite similar infarct size, females developed less pronounced abnormalities of LV diastolic filling. We hypothesize that the gender-related differences in postinfarction LV remodeling may contribute to the different LV filling patterns, and might ultimately relate to differences in clinical outcome.

Paradoxic Improvement in Regional Wall Motion During High-Dose Dobutamine Stress Echocardiography: A Marker for Hibernating Myocardium?

Dobutamine stress echocardiography detects myocardial ischemia by inducing regional left ventricular systolic dysfunction. Augmentation of wall motion in hypokinetic segments has also been noted with low-dose dobutamine, suggesting myocardial viability. We report a case of regional ventricular improvement during high-dose dobutamine therapy, which may represent relief from myocardial hibernation or changes in regional loading conditions.