Theano Papavassiliu

Volumetric Assessment of Epicardial Adipose Tissue With Cardiovascular Magnetic Resonance Imaging

Objective: Previous studies determined the amount of epicardial fat by measuring the right ventricular epicardial fat thickness. However, it is not proven whether this one‐dimensional method correlates well with the absolute amount of epicardial fat. In this prospective study, a new cardiovascular magnetic resonance imaging (CMR) method using the three‐dimensional summation of slices method was introduced to assess the total amount of epicardial fat.

Incidence and clinical significance of left ventricular thrombus in tako-tsubo cardiomyopathy assessed with echocardiography

BACKGROUND Left ventricular (LV) thrombus is a known complication of tako-tsubo cardiomyopathy (TC). However, current literature almost exclusively consists of isolated case reports. The aim of this study was to determine the incidence and clinical significance of LV thrombus formation in TC. METHODS AND RESULTS Over a 33-month period 52 patients with TC were assembled into a database at our institution. A retrospective database search was performed to identify patients with LV thrombus among these patients. LV thrombus, by echocardiography, was discovered in four patients[(8%); 95% confidence interval 3-19%]. Thrombus was present at the time of diagnosis in three patients. In one patient thrombus was absent initially and developed later. The LV apex was the site of thrombus formation in two patients, but the true apex was spared in the other two. All four patients had elevated serum levels of C-reactive protein (CRP). Two patients also had thrombocytosis. Treatment with low molecular weight heparin (LMWH) led to resolution of thrombus in all cases. CONCLUSION Our findings suggest that LV thrombus is a noteworthy complication in TC. It can occur both at initial presentation or at anytime later during the disease course. Elevated CRP levels and thrombocytosis may indicate a higher risk of thrombus formation.

Extent of late gadolinium enhancement detected by cardiovascular magnetic resonance correlates with the inducibility of ventricular tachyarrhythmia in hypertrophic cardiomyopathy

BackgroundMyocardial fibrosis is frequently identified in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to investigate the role of myocardial fibrosis detected by late gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) as a potential arrhythmogenic substrate in HCM. We hypothesized that the extent of LGE might be associated with the inducibility of ventricular tachyarrhythmias (VT) during programmed ventricular stimulation (PVS).MethodsWe evaluated retrospectively LGE CMR of 76 consecutive HCM patients, of which 43 presented with one or more risk factors for sudden cardiac death (SCD) and were therefore clinically classified as high-risk patients. Of these 43 patients, 38 additionally underwent an electrophysiological testing (EP). CMR indices and the extent of LGE, given as the % of LV mass with LGE were correlated with the presence of risk factors for SCD and the results of EP.ResultsHigh-risk patients had a significant higher prevalence of LGE than low-risk patients (29/43 [67%] versus 14/33 [47%]; p = 0.03). Also the % of LV mass with LGE was significantly higher in high-risk patients than in low-risk patients (14% versus 3%, p = 0.001, respectively). Of the 38 high- risk patients, 12 had inducible VT during EP. LV function, volumes and mass were comparable in patients with and without inducible VT. However, the % of LV mass with LGE was significantly higher in patients with inducible VT compared to those without (22% versus 10%, p = 0.03). The prevalence of LGE was, however, comparable between HCM patients with and those without inducible VT (10/12 [83%] versus 15/26 [58%]; p = 0.12). In the univariate analysis the % of LV mass with LGE and the septal wall thickness were significantly associated with the high-risk group (p = 0.001 and 0.004, respectively). Multivariate analysis demonstrated that the extent of LGE was the only independent predictor of the risk group (p = 0.03).ConclusionsThe extent of LGE in HCM patients correlated with risk factors of SCD and the likelihood of inducible VT. Furthermore, LGE extent was the only independent predictor of the risk group. This supports the hypothesis that the extent of fibrosis may serve as potential arrhythmogenic substrate for the occurrence of VT, especially in patients with clinical risk factors for SCD.

Insights into the location of type I ECG in patients with Brugada syndrome: Correlation of ECG and cardiovascular magnetic resonance imaging

BACKGROUND Brugada syndrome is characterized by ST-segment abnormalities in V1-V3. Electrocardiogram (ECG) leads placed in the 3rd and 2nd intercostal spaces (ICSs) increased the sensitivity for the detection of a type I ECG pattern. The anatomic explanation for this finding is pending. OBJECTIVE The purpose of the study was to correlate the location of the Brugada type I ECG with the anatomic location of the right ventricular outflow tract (RVOT). METHODS Twenty patients with positive ajmaline challenge and 10 patients with spontaneous Brugada type I ECG performed by using 12 right precordial leads underwent cardiovascular magnetic resonance imaging (CMRI). The craniocaudal and lateral extent of the RVOT and maximal RVOT area were determined. Type I ECG pattern and maximal ST-segment elevation were correlated to extent and maximal RVOT area, respectively. RESULTS In all patients, Brugada type I pattern was found in the 3rd ICS in sternal and left-parasternal positions. RVOT extent determined by using CMRI included the 3rd ICS in all patients. Maximal RVOT area was found in 3 patients in the 2nd ICS, in 5 patients in the 4th ICS, and in 22 patients in the 3rd ICS. CMRI predicted type I pattern with a sensitivity of 97.2%, specificity of 91.7%, positive predictive value of 88.6%, and negative predictive value of 98.0%. Maximal RVOT area coincided with maximal ST-segment elevation in 29 of 30 patients. CONCLUSION RVOT localization determined by using CMRI correlates highly with the type I Brugada pattern. Lead positioning according to RVOT location improves the diagnosis of Brugada syndrome.

Takotsubo cardiomyopathy is not due to plaque rupture: an intravascular ultrasound study.

Plaque rupture with subsequent transient thrombotic coronary occlusion by a fast‐dissolving clot is one of the proposed pathogenic mechanisms in Takotsubo cardiomyopathy (TC).

Takotsubo Cardiomyopathy (Acute Left Ventricular Apical Ballooning Syndrome) Occurring in the Intensive Care Unit

ObjectiveDiagnosis of Takotsubo cardiomyopathy (also known as stress cardiomyopathy or acute left ventricular apical ballooning syndrome) can be challenging in patients who are being treated for other diseases in the intensive care unit, because symptoms could erroneously be attributed to the underlying disease or patients may not experience symptoms due to analgesia and sedation. The aim of our study was to assess clinical features of Takotsubo cardiomyopathy occurring in the intensive care unit.DesignProspective observational study.SettingUniversity hospital.PatientsSix consecutive patients diagnosed with Takotsubo cardiomyopathy who were being treated for other diseases in the intensive care unit.InterventionsNone.Measurements and main resultsSudden hemodynamic deterioration (i.e., sudden hypotension, tachycardia or drop in monitored stroke volume) requiring vasopressor support was the presenting symptom in five of the six patients. Only one patient was able to report angina-like chest pain, all others were unable to experience symptoms due to analgesia and sedation. The electrocardiogram was abnormal in all patients upon diagnosis, demonstrating either ST-segment elevation (n = 2) and/or T-wave inversion (n = 5). Mild elevation of cardiac enzymes disproportionate to the extent of wall motion abnormalities on left ventriculography was present in all patients. All patients survived their acute event.ConclusionsSudden hemodynamic deterioration requiring vasopressor support and/or ECG abnormalities consisting of ST-segment elevation, ST-segment depression or T-wave inversion may be the presenting symptom of Takotsubo cardiomyopathy in the intensive care unit and should be included in the diagnostic algorithm.

Global and regional myocardial function quantification by two-dimensional strain in Takotsubo cardiomyopathy

AIMS This study sought to characterize global and regional systolic function in Takotsubo cardiomyopathy (TC) using two-dimensional (2D) strain imaging. METHODS AND RESULTS Twelve consecutive patients (11 women, 1 man) underwent 2D echocardiography on admission and on early follow-up (34 +/- 16 days). Two-dimensional images were analysed to measure longitudinal and radial strain and to calculate post-systolic shortening (PSS) and the post-systolic index (PSI). Mean age was 64 +/- 14 years. Upon presentation ejection fraction, average longitudinal and radial strains were 42 +/- 9%, -10.6 +/- 5.5%, and 20.1 +/- 17.3%, respectively. Values improved to 59 +/- 8%, -17.6 +/- 3.0%, and 50.2 +/- 17.0%, respectively (all P < 0.001). PSS was present in 69% of segments upon presentation and in 53% of segments upon follow-up. PSI was -0.16 at baseline and improved to -0.06 upon follow-up (P < 0.001). CONCLUSION Patients with TC show abnormal global and regional strain patterns during the acute phase of the disease which improve over time. However, subtle abnormalities of regional LV function seem to persist into the early follow-up period as suggested by the presence of PSS in more than half of LV segments. Long-term follow-up studies are needed to clarify whether these subtle abnormalities will further improve.

Noninvasive determination of cardiac output by the inert-gas-rebreathing method--comparison with cardiovascular magnetic resonance imaging.

Background: An easy, noninvasive and accurate technique for measuring cardiac output (CO) would be desirable for the diagnosis and therapy of cardiac diseases. Innocor, a novel inert-gas-rebreathing (IGR) system, has shown promising results in smaller studies. An extensive evaluation in a larger, less homogeneous patient collective is lacking. Methods: We prospectively assessed the accuracy and reproducibility of CO measurements obtained by IGR in 305 consecutive patients as compared to the noninvasive gold standard, cardiovascular magnetic resonance (CMR) imaging. Results: Bland-Altman analysis showed a good correspondence of the two methods for CO measurement with an average deviation of 0.2 ± 1.0 liters/min (mean ± SD) and a good reproducibility with a mean bias of 0.2 ± 0.5 liters/min. The accuracy of the present measurements at rest was significantly better in the physiological range than in higher or lower CO ranges. The error levels set forth by current recommendations were exceeded. Conclusion: The data show that IGR measurements are easy to perform and show good agreement with CMR; however, the technique appears to be less accurate in extreme CO ranges at rest. The clinical importance of the IGR method remains to be proven by further studies.

CMR findings in patients with hypertrophic cardiomyopathy and atrial fibrillation

ObjectivesWe sought to evaluate the relation between atrial fibrillation (AF) and the extent of myocardial scarring together with left ventricular (LV) and atrial parameters assessed by late gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM).BackgroundAF is the most common arrhythmia in HCM. Myocardial scarring is also identified frequently in HCM. However, the impact of myocardial scarring assessed by LGE CMR on the presence of AF has not been evaluated yet.Methods87 HCM patients underwent LGE CMR, echocardiography and regular ECG recordings. LV function, volumes, myocardial thickness, left atrial (LA) volume and the extent of LGE, were assessed using CMR and correlated to AF. Additionally, the presence of diastolic dysfunction and mitral regurgitation were obtained by echocardiography and also correlated to AF.ResultsEpisodes of AF were documented in 37 patients (42%). Indexed LV volumes and mass were comparable between HCM patients with and without AF. However, indexed LA volume was significantly higher in HCM patients with AF than in HCM patients without AF (68 ± 24 ml·m-2 versus 46 ± 18 ml·m-2, p = 0.0002, respectively). The mean extent of LGE was higher in HCM patients with AF than those without AF (12.4 ± 14.5% versus 6.0 ± 8.6%, p = 0.02). When adjusting for age, gender and LV mass, LGE and indexed LA volume significantly correlated to AF (r = 0.34, p = 0.02 and r = 0.42, p < 0.001 respectively). By echocardiographic examination, LV diastolic dysfunction was evident in 35 (40%) patients. Mitral regurgitation greater than II was observed in 12 patients (14%). Multivariate analysis demonstrated that LA volume and presence of diastolic dysfunction were the only independent determinant of AF in HCM patients (p = 0.006, p = 0.01 respectively). Receiver operating characteristic curve analysis indicated good predictive performance of LA volume and LGE (AUC = 0.74 and 0.64 respectively) with respect to AF.ConclusionHCM patients with AF display significantly more LGE than HCM patients without AF. However, the extent of LGE is inferior to the LA size for predicting AF prevalence. LA dilation is the strongest determinant of AF in HCM patients, and is related to the extent of LGE in the LV, irrespective of LV mass.

Global and regional myocardial function quantification in Takotsubo cardiomyopathy in comparison to acute anterior myocardial infarction using two-dimensional (2D) strain echocardiography.

Aims: This study sought to compare global and regional myocardial function in Takotsubo cardiomyopathy (TC) to that in acute anterior myocardial infarction (AMI) using 2D strain imaging. Methods: Twelve consecutive patients with TC (ten women, two men) and 12 patients with AMI (four women, eight men) underwent 2D echocardiography at initial presentation. 2D strain images were analyzed to measure longitudinal and radial strain. Global strain was calculated as the average longitudinal strain of the segments of two‐, three‐, and four‐chamber views. Biplane ejection fraction was assessed using Simpsons biplane method. Results: Significant differences in radial strain (TC vs. AMI) were found in lateral (13.5 ± 10.1% vs. 25.1 ± 11.2%, P = 0.035), posterior (15.2 ± 14.5% vs. 51.4 ± 14.2%, P < 0.001), and inferior (17.9 ± 15.5% vs. 49.4 ± 16.9%, P = 0.002) segments. Longitudinal strain was significantly lower in TC in basal‐inferior (−15.8 ± 9.2% vs. −22.7 ± 3.8%, P = 0.037), midinferior (−8.3 ± 9.2% vs. −16.8 ± 3.0%, P = 0.004), basal‐posterior (−12.2 ± 9.4% vs. −21.6 ± 4.4%, P = 0.016), midposterior (−4.4 ± 8.0% vs. −15.4 ± 3.5%, P = 0.002), apical‐posterior (2.3 ± 6.7% vs. −6.4 ± 10.1%, P = 0.023), and midlateral (−3.4 ± 6.9% vs. −9.5 ± 5.8%, P = 0.028) segments. Global strain and ejection fraction were significantly higher in patients with AMI (−3.5 ± 8.2% vs. −10.3 ± 8.4%, P < 0.001 and 37 ± 11% vs. 46 ± 11%, P = 0.045). Conclusion: In TC, strain was reduced around the entire mid left‐ventricular circumference, whereas in AMI it was predominantly reduced in the anterior and anteroseptal wall. These observed differences confirm the notion that TC affects myocardium beyond the territory of a single coronary artery. They may allow noninvasive distinction between both entities. (Echocardiography 2011;28:715‐719)