Right ventricular function and dyssynchrony in Brugada syndrome: Highlighting the importance of the mechanical substrate in the right ventricular outflow tract.

BACKGROUND: Current evidence suggests that Brugada syndrome (BrS), far from being a purely electrical condition, is associated with subtle mechanical abnormalities primarily affecting the right ventricle (RV). We aimed to characterize RV function in BrS and investigate the echocardiographic profile of patients with arrhythmic events, with a special focus on parameters of RV dyssynchrony using speckle-tracking echocardiography (STE). METHODS: An echocardiogram was performed in 71 BrS patients and 25 healthy controls. STE was performed to assess regional and global RV mechanics, including RV outflow tract shortening (RVOTS). RVOT contraction time was considered to calculate the modified RV mechanical dispersion (RVMDm). Arrhythmic events were prospectively evaluated in the BrS cohort. RESULTS: Compared to controls, BrS patients showed subtle contractile abnormalities, including impaired RV longitudinal strain, higher RV index of myocardial performance (RIMP) and lower RVOTS. BrS patients also exhibited a greater contraction delay between the lateral and the septal aspect of the RV. After a median follow-up of 7.3 year (IQR 5.2-10.8), 6 patients presented malignant arrhythmic events. RIMP >0.50, RVOTS <16.2% and RVMDm > 42 ms showed high sensitivity for the identification of BrS patients with arrhythmic events during follow-up. CONCLUSIONS: Subtle RV mechanical abnormalities were present in BrS patients. RIMP and RVOTS, a novel STE-derived parameter, were found to be sensitive markers of arrhythmic events. Adding the RVOT contraction time to the analysis of RVMD may help identify patients at higher risk, reflecting the importance of the RVOT mechanical substrate in the assessment of the arrhythmic risk in BrS.

Left atrial strain in the assessment of diastolic function: providing new insights into primary myocardial dysfunction in Marfan syndrome.

Previous studies using conventional echocardiographic measurements have reported subclinical left ventricular (LV) diastolic abnormalities in patients with Marfan syndrome (MFS). Left atrial (LA) strain allows an accurate categorization of LV diastolic dysfunction. We aimed to characterize LV myocardial performance in a cohort of MFS patients using STE-derived measurements (LV and LA strain) along with conventional echocardiographic parameters. We studied 127 adult patients with MFS (no prior cardiac surgery or significant valvular regurgitation) and 38 healthy controls. We performed detailed echocardiograms and selected left atrial reservoir strain (LASr) as a surrogate of impaired relaxation. Additionally, we searched for possible determinants of LASr in patients with MFS, with a special focus on the elastic properties of the aorta. In spite of lower E-wave, septal and lateral e' velocities and average E/e' ratio in MFS patients, all participants had normal diastolic function according to current guidelines. MFS patients exhibited reduced LV global longitudinal strain (19.3 ± 2.6 vs 21.6 ± 2.1%, p < 0.001) and reduced LASr (32.9 ± 8.5 vs 43.3 ± 7.8%, p < 0.001) compared to controls. In the MFS cohort, we found weak significant (p < 0.05) correlations between LASr and certain parameters: E/A ratio (R = 0.258), E wave (R = 0.226), aortic distensibility (R = 0.222), stiffness index (R = - 0.216), LV ejection fraction (R = 0.214), lateral e' (R = 0.210), LV end-systolic volume index (R = - 0.210), LV global longitudinal strain (R = 0.201), septal e' (R = 0.185). After multivariate analysis, only LV end-systolic volume index and E/A ratio maintained a weak independent association with LASr (R = - 0.220; p = 0.017 and R = 0.199; p = 0.046, respectively). In conclusion, LASr is reduced in patients with MFS, which may represent an early stage of LV diastolic dysfunction. LASr is not determined by the elastic properties of the aorta, suggesting that impaired myocardial relaxation is a primary condition in MFS.

Predictors of lack of response to resynchronization therapy.

About 30% of patients treated with cardiac resynchronization therapy (CRT) do not respond to treatment. The aim of this study was to identify clinical predictors of lack of improvement in patients receiving CRT. From 197 consecutive patients scheduled to receive CRT, 143 fulfilled the inclusion criteria. Mean age was 68 +/- 7 years and 79% were men. Heart failure was due to ischemic heart disease in 49 patients (34%). Mean QRS duration was 165 +/- 26 ms, and left ventricular ejection fraction was 27 +/- 7%. Nonresponder patients were defined as those who died of heart failure, underwent heart transplantation, or did not increase the distance walked in 6 minutes >10%. At 6-month follow-up, there were 28 nonresponders (20%). Among nonresponders, 2 patients received a heart transplantation and 9 patients died of heart failure. In logistic regression analysis, independent predictors of lack of response to CRT were ischemic heart disease (odds ratio [OR] 2.9, 95% confidence interval [CI] 1.2 to 7; p = 0.023), severe mitral regurgitation (OR 3.5, 95% CI 1.3 to 9; p = 0.014), and left ventricular end-diastolic diameter > or =75 mm (OR 3.1, 95% CI 1.1 to 8; p = 0.026). Patients with these 3 predictors had a probability response of 27%.

Airmed-cardio: a GSM and Internet services-based system for out-of-hospital follow-up of cardiac patients.

A platform built around three information entities (patient, health-care_agent, and central_station) was designed to enable patients with chronic heart disease (in stable condition; emergency situations were excluded deliberately) to complete specifically defined protocols for out-of-hospital follow-up and monitoring. The patients belonged to one of four specific risk groups: arterial hypertension, malignant arrhythmias, heart failure, and postinfarction rehabilitation. They were provided with portable recording equipment and a cellular phone that supported data transmission [electrocardiogram (ECG)] and wireless application protocol (WAP) (remaining parameters and ad hoc questionnaires). The central station was an automatized platform, with no human operator. The information received was organized chronologically in patient folders. The health-care_agents had continuous and secure access to the patient folders, through tools based on the world wide web and WAP, and to short messages sent by their patients. A pilot project was conducted with 89 patients (mean length of participation: 50.1 days). A total of 2168 ECGs (mean duration transmission = 2 min/30 s; network errors < 0.1%) and 4011 short messages (none lost, in 95% of cases 30 s < delay < 1 min) were transmitted; 6083 WAP sessions (mean duration = 3 min 11 s; network failures < 0.1%) were The functionality of the platform was also evaluated, analyzing the subjective component of usability, showing the evolution of patient acceptance over time.

[Valve repair for chronic mitral regurgitation]. / Reparación valvular en la insuficiencia mitral crónica.

Valve repair is the best surgical treatment for mitral regurgitation. In the present article we describe the results of mitral valve repair in patients with chronic mitral regurgitation treated at our center during the last eight years. The degree of correction of valve insufficiency, functional benefit, in-hospital morbidity and mortality, postoperative outcome of ventricular function, and middle-term overall and reoperation-free survival are analyzed.

Magnetic Resonance for Noninvasive Detection of Microcirculatory Disease Associated With Allograft Vasculopathy: Intracoronary Measurement Validation.

INTRODUCTION AND OBJECTIVES: Cardiac allograft vasculopathy affects both epicardial and microcirculatory coronary compartments. Magnetic resonance perfusion imaging has been proposed as a useful tool to assess microcirculation mostly outside the heart transplantation setting. Instantaneous hyperemic diastolic flow velocity-pressure slope, an intracoronary physiology index, has demonstrated a better correlation with microcirculatory remodelling in cardiac allograft vasculopathy than other indices such as coronary flow velocity reserve. To investigate the potential of magnetic resonance perfusion imaging to detect the presence of microcirculatory remodeling in cardiac allograft vasculopathy, we compared magnetic resonance perfusion data with invasive intracoronary physiological indices to study microcirculation in a population of heart transplantation recipients with macrovascular nonobstructive disease demonstrated with intravascular ultrasound. METHODS: We studied 8 heart transplantation recipients (mean age, 61 [12] years, 100% male) with epicardial allograft vasculopathy defined by intravascular ultrasound, nonsignificant coronary stenoses and negative visually-assessed wall-motion/perfusion dobutamine stress magnetic resonance. Quantitative stress and rest magnetic resonance perfusion data to build myocardial perfusion reserve index, noninvasively, and 4 invasive intracoronary physiological indices were determined. RESULTS: Postprocessed data showed a mean (standard deviation) myocardial perfusion reserve index of 1.22 (0.27), while fractional flow reserve, coronary flow velocity reserve, hyperemic microvascular resistance and instantaneous hyperemic diastolic flow velocity-pressure slope were 0.98 (0.02), cm/s/mmHg, 2.34 (0.55) cm/s/mmHg, 2.00 (0.69) cm/s/mmHg and 0.91 (0.65) cm/s/mmHg, respectively. The myocardial perfusion reserve index correlated strongly only with the instantaneous hyperemic diastolic flow velocity-pressure slope (r=0.75; P=.033). CONCLUSIONS: Myocardial perfusion reserve index derived from a comprehensive dobutamine stress magnetic resonance appears to be a reliable technique for noninvasive detection of microcirculatory coronary disease associated with cardiac allograft vasculopathy.

Usefulness of Two-Dimensional Strain Parameters to Diagnose Acute Rejection after Heart Transplantation.

BACKGROUND: Acute cellular rejection (ACR) is still a relevant complication after orthotopic heart transplantation. The diagnosis of ACR is based on endomyocardial biopsy (EMB). Recent advances in two-dimensional strain imaging may allow early noninvasive detection of ACR. The objective of this study was to analyze the usefulness of conventional and new echocardiographic parameters to exclude ACR after orthotopic heart transplantation. METHODS: Thirty-four consecutive adult heart transplant recipients admitted to a single center between January 2010 and December 2012 for orthotopic heart transplantation were prospectively included. A total of 235 pairs of EMB and echocardiographic examination were performed. A median of seven studies per patient (interquartile range, six to eight studies per patient) were performed during the first year of follow-up. Classic echocardiographic parameters; speckle-tracking-derived left ventricular (LV) longitudinal, radial, and circumferential strain; and global and free wall right ventricular (RV) longitudinal strain were analyzed. RESULTS: ACR was detected in 26.4% of EMB samples (n = 62); 5.1% (n = 12) required specific treatment (ACR degree ≥ 2R). Lower absolute values of global LV longitudinal strain and free wall RV longitudinal strain were present in patients with ACR degree ≥ 2R compared with those without ACR (13.7 ± 2.7% vs 17.8 ± 3.4% and 16.6 ± 3.6% vs 23.3 ± 5.2%, respectively). An average LV longitudinal strain < 15.5% had 85.7% sensitivity, 81.4% specificity, 98.8% negative predictive value, 25.0% positive predictive value, and 81.7% accuracy for the presence of ACR degree ≥ 2R. Free wall RV longitudinal strain < 17% had 85.7% sensitivity, 91.1% specificity, 98.8% negative predictive value, 42.9% positive predictive value, and 90.7% accuracy for ACR degree ≥ 2R. Both variables were normal in 106 echocardiograms (57.6%); none of these patients presented with ACR degree ≥ 2R. CONCLUSIONS: The combination of two new echocardiographic measures, global LV and RV free wall longitudinal strain, may be able to identify a group of heart transplant patients who are unlikely to have ACR. If these findings are confirmed independently, it may be possible to use LV and RV strain measures as reliable tools to exclude ACR and to reduce the burden of repeated EMB.

[Surgical treatment for hypertrophic obstructive cardiomyopathy]. / Tratamiento quirúrgico de la miocardiopatía hipertrófica obstructiva.

INTRODUCTION AND OBJECTIVES: Five percent of the patients with hypertrophic obstructive cardiomyopathy (HOCM) have symptoms unresponsive to medical treatment and are candidates for invasive therapy. The objective of this study was to analyze our results with surgical treatment of HOCM during the last 10 years. PATIENTS AND METHOD: Between July 1993 and January 2004 26 patients with HOCM refractory to drug therapy were operated on. An extended septal myectomy was performed, in combination with anterior mitral leaflet plication in 19 cases (73%) and with mitral valve replacement in 5 (19%). Evolution of the grade of dyspnea, left ventricle outflow tract gradient (LVOTG), mitral regurgitation, and systolic anterior motion after surgery was analyzed. RESULTS: Mean follow-up was 63 (37) months. After surgery, a significant reduction in LVOTG (from 96.5 to 19.5 mmHg; P<.001), grade of mitral regurgitation (from 2.54 to 0.69; P<.001) and systolic anterior motion (from 2.92 to 0.23; P<.001) was achieved, which led to improvement in functional class. Hospital mortality and need for pacemaker implantation due to complete heart block after surgery was 3.8% (n=1). There were no cases of iatrogenic ventricular septal defect or mitro-aortic valve injury. Actuarial survival at 5 years was 96% (4%). CONCLUSIONS: Surgery in patients with HOCM yields great clinical improvements with low morbidity and mortality. Simultaneous intervention for both myocardial and valvular components of the disease allows not only reduction in the LVOTG but also correction of mitral regurgitation and abolition of systolic anterior motion.

Erysipelas and acute myocarditis: an unusual combination.

Myocarditis is a rare disease with variable clinical presentation and diverse electrocardiographic and echocardiographic features. Viral infection is the most common cause, but myocarditis can also be caused by bacterial infection. The most frequently involved bacterial agent is group A Streptococcus, which is also an etiologic agent of erysipelas. We present the case of a man aged 46 years with left-leg erysipelas who developed myocarditis. Cardiac magnetic resonance played an essential role in diagnosis. This case is, to our knowledge, the first description of an association between erysipelas and myocarditis.

Cardiac magnetic resonance imaging in the diagnosis of myocarditis mimicking myocardial infarction.

Cardiac Magnetic Resonance (CMR) imaging has recently become a very useful tool in the diagnosis of myocarditis. We describe a patient in whom acute myocarditis was presented as an acute myocardial infarction and had an atypical course with rapid normalization of ECG abnormalities. In this case CMR imaging was essential to confirm the diagnosis of myocarditis.