Paolo Trambaiolo

Doppler myocardial imaging to evaluate the effectiveness of pacing sites in patients receiving biventricular pacing

OBJECTIVES The goal of this study was to compare the efficacy of biventricular pacing (BIV) at the most delayed wall of the left ventricle (LV) and at other LV walls. BACKGROUND Biventricular pacing could provide additional benefit when it is applied at the most delayed site. METHODS In 31 patients with advanced nonischemic heart failure, the activation delay was defined, in blind before BIV, by regional noninvasive Tissue Doppler Imaging as the time interval between the end of the A-wave (C point) and the beginning of the E-wave (O point) from the basal level of each wall. The left pacing site was considered concordant with the most delayed site when the lead was inserted at the wall with the greatest regional interval between C and O points (CO(R)). After BIV, patients were divided into group A (13/31) (i.e., paced at the most delayed site) and group B (18/31) (i.e., paced at any other site). RESULTS After BIV, in all patients LV end-diastolic (LVEDV) and end-systolic (LVESV) volumes decreased (p = 0.025 and 0.001), LV ejection fraction (LVEF) increased (p = 0.002), QRS narrowed (p = 0.000), New York Heart Association class decreased (p = 0.006), 6-min walked distance (WD) increased (p = 0.046), the interval between closure and opening of mitral valve (CO) and isovolumic contraction time (ICT) decreased (p = 0.001 and 0.000), diastolic time (EA) and Q-P(2) interval increased (p = 0.003 and 0.000), while Q-A(2) interval and mean performance index (MPI) did not change. Group A showed greater improvement over group B in LVESV (p = 0.04), LVEF (p = 0.04), bicycle stress testing work (p = 0.03) and time (p = 0.08) capacity, CO (p = 0.04) and ICT (p = 0.02). CONCLUSIONS After BIV, LV performance improved significantly in all patients; however, the greatest improvement was found in patients paced at the most delayed site.

Biventricular pacing in heart failure: back to basics in the pathophysiology of left bundle branch block to reduce the number of nonresponders

Cardiac resynchronization therapy is a novel nonpharmacologic approach to treating patients who have advanced heart failure with left bundle branch block (LBBB). Such a therapy is based on the original theory that synchronous biventricular pacing is able to reduce the interventricular delay caused by LBBB in patients with heart failure. Although there is convincing evidence that biventricular pacing increases the left ventricular ejection fraction, decreases mitral regurgitation, and improves symptoms caused by heart failure, the percentage of nonresponders to such therapy has been described as high as about one third of patients with heart failure having LBBB. Factors responsible for this relatively high prevalence are reviewed, the most important of them probably being left intraventricular dyssynchrony, which can persist after biventricular pacing, notwithstanding right and left interventricular resynchronization. Such a dyssynchrony, as evaluated by tissue Doppler imaging, may be because of the discordance between the site of the left ventricular pacing and the site of the left ventricular delay. Therefore, to characterize the pathophysiologic pattern of LBBB, the investigators suggest an assessment of the electromechanical dysfunction with a noninvasive reliable technique, such as tissue Doppler imaging, which can be repeated after biventricular pacing.

A hand-carried cardiac ultrasound device in the outpatient cardiology clinic reduces the need for standard echocardiography

Objective: To assess the potential value and cost-effectiveness of a hand-carried ultrasound (HCU) device in an outpatient cardiology clinic. Methods: 222 consecutive patients were prospectively enrolled in the study. When standard echocardiography (SE) was specifically indicated on the basis of clinical history, electrocardiogram and physical examination, the same cardiologist (level-2 or level-3 trained) immediately performed an HCU examination. The cardiologist then reassessed the clinical situation to confirm or cancel the SE request according to the information provided by HCU. The SE examination was performed by a sonographer and examined in a blinded fashion by a cardiologist expert in echocardiography. Findings from the two examinations were compared. Results: HCU was performed in 108/222 patients, and a definite diagnosis was established in 34 of them (31%), making SE examination potentially avoidable. In the 74 patients with inconclusive HCU results and for whom SE was still indicated, the decision was mainly dictated by the lack of spectral Doppler modality in the HCU system. The overall agreement between HCU and SE for diagnosis of normal/abnormal echocardiograms was 73% (κ = 0.4). On the basis of the potentially avoided SE examinations and the obviated need for a second cardiac consultation, a total cost saving of €2142 per 100 patients referred for echocardiography was estimated. Conclusions: The use of a simple HCU device in the outpatient cardiology clinic allowed reliable diagnosis in one third of the patients referred for echocardiography, which translates into cost and time saving benefits.

Stress echo 2020: the international stress echo study in ischemic and non-ischemic heart disease

BackgroundStress echocardiography (SE) has an established role in evidence-based guidelines, but recently its breadth and variety of applications have extended well beyond coronary artery disease (CAD). We lack a prospective research study of SE applications, in and beyond CAD, also considering a variety of signs in addition to regional wall motion abnormalities.MethodsIn a prospective, multicenter, international, observational study design, > 100 certified high-volume SE labs (initially from Italy, Brazil, Hungary, and Serbia) will be networked with an organized system of clinical, laboratory and imaging data collection at the time of physical or pharmacological SE, with structured follow-up information. The study is endorsed by the Italian Society of Cardiovascular Echography and organized in 10 subprojects focusing on: contractile reserve for prediction of cardiac resynchronization or medical therapy response; stress B-lines in heart failure; hypertrophic cardiomyopathy; heart failure with preserved ejection fraction; mitral regurgitation after either transcatheter or surgical aortic valve replacement; outdoor SE in extreme physiology; right ventricular contractile reserve in repaired Tetralogy of Fallot; suspected or initial pulmonary arterial hypertension; coronary flow velocity, left ventricular elastance reserve and B-lines in known or suspected CAD; identification of subclinical familial disease in genotype-positive, phenotype- negative healthy relatives of inherited disease (such as hypertrophic cardiomyopathy).ResultsWe expect to recruit about 10,000 patients over a 5-year period (2016-2020), with sample sizes ranging from 5,000 for coronary flow velocity/ left ventricular elastance/ B-lines in CAD to around 250 for hypertrophic cardiomyopathy or repaired Tetralogy of Fallot. This data-base will allow to investigate technical questions such as feasibility and reproducibility of various SE parameters and to assess their prognostic value in different clinical scenarios.ConclusionsThe study will create the cultural, informatic and scientific infrastructure connecting high-volume, accredited SE labs, sharing common criteria of indication, execution, reporting and image storage of SE to obtain original safety, feasibility, and outcome data in evidence-poor diagnostic fields, also outside the established core application of SE in CAD based on regional wall motion abnormalities. The study will standardize procedures, validate emerging signs, and integrate the new information with established knowledge, helping to build a next-generation SE lab without inner walls.

Echocardiographic estimation of pulmonary pressures.

Cardiac ultrasound plays a pivotal role in assessing pulmonary artery pressures. Estimation of right atrial pressure can be derived from the dimensions and respiratory variation of the inferior vena cava and Doppler modalities provide an accurate and comprehensive evaluation of right ventricular and pulmonary artery pressures. Peak pulmonary artery pressure can be calculated from continuous wave Doppler sampling of the tricuspid regurgitant jet, while pulsed wave Doppler sampling of the pulmonary regurgitant jet allows evaluation of mean and diastolic pulmonary artery pressures. In patients with tricuspid regurgitation that is either absent or not adequately detectable by Doppler method, Doppler right ventricular outflow tract investigation can be helpful. Recent data indicate that analysis of right ventricular function using myocardial Doppler echocardiography may also provide new insights for the non-invasive estimation of pulmonary artery pressures. In particular, right ventricular isovolumic relaxation time measured by myocardial Doppler echocardiography at the tricuspid annulus may provide an alternative method for estimating pulmonary artery pressure, especially in patients with tricuspid regurgitation not detectable or spectral Doppler not properly interpretable.

FROM DIGITAL IMAGE PROCESSING OF COLOUR DOPPLER M-MODE MAPS TO NONINVASIVE EVALUATION OF THE LEFT VENTRICULAR DIASTOLIC FUNCTION: A DEDICATED SOFTWARE PACKAGE

Noninvasive estimation of diastolic pressure gradients has recently been validated using the space-temporal velocity distribution available from colour Doppler M-mode (CDM). However, the methods currently applied for analysing CDM patterns of left ventricular (LV) filling have limitations, such as lack of automation, subjective variability and limited use of digital velocity map. For this reason, we have developed software able to acquire and process the CDM maps; thus, providing an easily interpretable graphical and numerical display. The pressure field is obtained by approximating the derivatives with centred finite differences via the incompressible Navier-Stokes equations. After digital filtering of the noise and the removal of the colour black spots, the velocity field is utilised to compute the pressure gradient field and the pressure values by spatial integration. It is concluded that automatic quantification of colour CDM patterns is feasible and will be a strategic tool in the investigation of one of the most intriguing topics in cardiology.

Transthoracic Doppler echocardiography for the assessment of left atrial appendage size and blood flow velocity: a multicentre study.

Objective The aim of this study was to evaluate the reliability of transthoracic Doppler echocardiography (TTE) in the assessment of left atrial appendage (LAA) size and function. Methods We considered 86 consecutive patients [56 male, 30 female; mean age 64 ± 13 years, sinus rhythm 36 patients (42%); atrial flutter/fibrillation 50 patients (58%)] referred for transoesophageal echocardiography (TEE) and TTE. Maximum LAA transverse diameters and LAA peak flow velocities were calculated by two-dimensional and pulsed-wave Doppler analysis at TEE and TTE. Results LAA systolic transverse diameters were detectable in 78 patients (91%) by TTE and showed a significant correlation with TEE (r = 0.77, P < 0.0001). LAA peak flow velocities were measurable by TTE in 72 patients (84%) and were comparable with TEE (50.4 ± 23 vs 47.3 ± 23.2 cm/s, r = 0.67, P < 0.0001). A peak blood flow velocity of <25 cm/s at TTE was the best indicator of very low (<20 cm/s) LAA flow velocity as detected by TEE (sensitivity 93%, specificity 87%, area under the curve 0.94, P < 0.0001). Conversely, a peak blood flow velocity of >56 cm/s at TTE indicated a very high (> 40 cm/s) LAA flow velocity as detected by TEE (sensitivity 50%, specificity 96%, area under the curve 0.87; P < 0.0001). Conclusions Reliable LAA size and blood flow velocities can be obtained by TTE in consecutive, unselected patients. TTE identifies patients with low and high blood flow velocities in the LAA, providing helpful information for the definition of individual embolic risk.

ROLE OF PASSIVE LEG RAISING TO EVALUATE PRELOAD RESPONSIVENESS IN PATIENTS WITH CARDIOGENIC SHOCK AFTER ST ELEVATION MYOCARDIAL INFARCTION (STEMI) TREATED WITH INOTROPIC THERAPY

Optimal cardiac filling is essential for maintaining an adequate cardiac output and organ perfusion in patients with cardiogenic shock (CS) after STEMI). Passive leg raising (PLR) represents a “self-volume challenge” that could predict fluid response; the transient hemodynamic effect of