Left Atrial Deformation in Heart Failure: A Clinical Update.

Despite left ventricular global longitudinal strain is an eminent and validated marker of cardiovascular disease, assessment of left atrial size and function may have incremental role in diagnosis and management of cardiovascular disease. Left atrial strain, measured by 2-dimensional speckle tracking echocardiography, is a non-invasive biomarker for the assessment of left atrial function. This novel marker, has additional value to traditional echocardiography markers of left atrial function such as left atrial diameter and volume for the diagnosis and management of left ventricular diastolic dysfunction, heart failure with preserved ejection fraction, atrial fibrillation and valvular disease. However, there are potent limitations for its use in the daily clinical practice, regarding loading conditions, image acquisition and heart rate. The aim of this review is to summarize the published evidence about left atrial strain, as assessed by speckle tracking imaging, and to discuss its clinical implications and its potent limitations.

Low-Dose Dobutamine Stress Echocardiography for the Early Detection of Pulmonary Arterial Hypertension in Selected Patients with Systemic Sclerosis Whose Resting Echocardiography Is Non-Diagnostic for Pulmonary Hypertension.

BACKGROUND: Dobutamine stress echocardiography (DSE) has limited application in systemic sclerosis (SSc). We examined DSE usefulness in revealing pulmonary arterial hypertension (PAH) in selected SSc patients whose resting echocardiography for pulmonary hypertension (PH) was non-diagnostic. METHODS: Forty SSc patients underwent right heart catheterization (RHC) and, simultaneously, low-dose DSE (incremental doses up to 20 µg/kg/min). Inclusion criteria were: preserved left and right ventricular (RV) function (tricuspid annulus plane systolic excursion [TAPSE] ≥ 16 mm and tissue Doppler imaging-derived systolic velocity of tricuspid annulus [RVS'] > 10 cm/s), normal pulmonary function tests, and baseline maximal tricuspid regurgitation (TR) velocity of 2.7-3.2 m/s. RESULTS: Of 36 patients who completed DSE, resting RHC diagnosed PAH in 12 patients (33.3%). At 20 µg/kg/min, patients with PAH had higher TR velocity, higher pulmonary arterial pressure measured by RHC, and lower RV inotropic response compared with patients without PAH. A cut-off value of maximal TR velocity >3.1 m/s had a sensitivity of 80%, a specificity of 84.2%, and an accuracy of 82.4% for the detection of PAH. CONCLUSIONS: Low-dose DSE has a satisfactory diagnostic accuracy for the early detection of PAH in highly selected SSc patients whose baseline echocardiographic measurements for PH lie in the gray zone.

The Role of Exercise Doppler Echocardiography to Unmask Pulmonary Arterial Hypertension in Selected Patients with Systemic Sclerosis and Equivocal Baseline Echocardiographic Values for Pulmonary Hypertension.

Recently, a lower mean pulmonary arterial pressure (PAP) cutoff of >20 mmHg for pulmonary hypertension (PH) definition has been proposed. We examined whether exercise Doppler echocardiography (EDE) can unmask PA hypertension (PAH) in systemic sclerosis (SSc) patients whose baseline echocardiography for PH is equivocal. We enrolled 49 patients with SSc who underwent treadmill EDE. Tricuspid regurgitation (TR) velocity was recorded immediately after EDE. Inotropic reserve of right ventricle (RV) was assessed by the change (post-prior to exercise) of tissue Doppler imaging-derived peak systolic velocity (S) of tricuspid annulus. Inclusion criteria comprised preserved left and RV function, and baseline TR velocity between 2.7 and 3.2 m/s. All patients had right-heart catheterization (RHC) within 48 h after EDE. From 46 patients with good quality of post-exercise TR velocity, RHC confirmed PAH in 21 (45.6%). Post-exercise TR velocity >3.4 m/s had a sensitivity of 90.5%, a specificity of 80% and an accuracy of 84.8% in detecting PAH. Inotropic reserve of RV was positively correlated with maximum achieved workload in METs (r = 0.571, p < 0.001). EDE has a good diagnostic accuracy for the identification of PAH in selected SSc patients whose baseline echocardiographic measurements for PH lie in the gray zone, and it is also potentially useful in assessing RV contractile reserve.

Optimal Blood Pressure Control Improves Left Ventricular Torsional Deformation and Vascular Function in Newly Diagnosed Hypertensives: a 3-Year Follow-up Study.

We investigated the effects of optimizing blood pressure control on cardiac deformation and vascular function. For this purpose, in 200 untreated patients with essential hypertension, we assessed at baseline as well as after 3 years of optimal blood pressure control: arterial stiffness and coronary microcirculatory function as well as longitudinal and torsional deformation parameters. Compared to baseline, after 3 years of optimal blood pressure control, there was an improvement of longitudinal strain, twisting as well as untwisting parameters of the left ventricle. In parallel, there was an improvement in coronary microcirculatory function, arterial stiffness, left ventricular mass, and ventricular-arterial interaction. The reduction of arterial stiffness was independently associated with the respective improvement of cardiac deformation markers and coronary flow reserve after adjusting for blood pressure improvement. Blood pressure optimization improves LV longitudinal and torsional mechanics in hypertensives in parallel with arterial stiffness, resulting in improved ventricular-arterial interaction and coronary flow reserve. Trial registration: ClinicalTrials.gov Identifier: NCT02346695.

Pulse wave velocity to global longitudinal strain ratio in hypertension.

BACKGROUND: Arterial elastance to left ventricular elastance ratio assessed by echocardiography is widely used as a marker of ventricular-arterial coupling. MATERIALS AND METHODS: We investigated whether the ratio of carotid-femoral pulse wave velocity, as a marker of arterial stiffness, to global longitudinal strain, as a marker of left ventricular performance, could be better associated with vascular and cardiac damage than the established arterial elastance/left ventricular elastance index. In 299 newly-diagnosed untreated hypertensives we measured, carotid-femoral pulse wave velocity, and carotid intima-media thickness, coronary-flow reserve, arterial elastance/left ventricular elastance, global longitudinal strain, and markers of left ventricular diastolic function (E/A and E') by echocardiography. RESULTS: Pulse wave velocity-to-global longitudinal strain ratio (PWV/GLS) was lower in hypertensives than controls (-0.61 ± 0.21 vs -0.45 ± 0.11 m/sec%, P < 0.001). Low PWV/GLS values were associated with carotid-intima media thickness > 0.9 mm (P = 0.003), E/A ≤ 0.8 (P = 0.019) and E' ≤ 9 cm/sec (P = 0.002) and coronary-flow reserve < 2.5 (P = 0.017), after adjustment for age, sex and mean arterial pressure. Low PWV/GLS was also associated with increased left ventricular mass and left atrial volume in the univariate (P = 0.003 and 0.038) but not in the multivariate model. In hypertensives, there was no significant association of arterial elastance-to-left ventricular elastance index with carotid intima media thickness, coronary flow reserve, E/A, E', or left atrial volume with the exception of an inverse association with left ventricular mass (P = 0.027). CONCLUSIONS: Pulse wave velocity-to-global longitudinal strain ratio but not the echocardiography-derived arterial elastance-to left ventricular elastance index is related to impaired carotid-intima media thickness, coronary-flow reserve and diastolic function in hypertensives.

A safety radiation marker in the cardiac catheterization lab.

OBJECTIVE: Nowadays, in order to deal with cardiovascular disease, coronary angiography (CRA) is the best tool and gold standard for diagnosis and assessment. CRA inevitably exposes both patient and operator to radiation. The purpose of this study was to calculate the radiation exposure in association with the radiation absorbed by interventional cardiologists, in order to estimate a safety radiation marker in the catheterization laboratory. METHODS AND RESULTS: In 794 successive patients undergoing CRA and in three interventional cardiologists the following parameters were examined: radioscopy duration, radiation exposure during fluoroscopy, total radiation exposure and the number of stents per procedure. Every interventional cardiologist was exposed to 562,936 µGym2 of total radiation during CRA procedures, to 833,371 µGym2 during elective CRA + percutaneous coronary intervention (PCI) procedures and to 328,250 µGym2 during primary CRA + PCI. Hence, the total amount of radiation that every angiographer was exposed to amounted to 1,724,557.5 µGym2 (median values). During the same period, the average radiation that every angiographer absorbed was 15,253 while the average dose of radiation absorbed during one procedure was 0.06 mSv for each operator. Therefore, the ratio between radiation exposure and the radiation finally absorbed by every operator was 113:1 µGym2/mSv. CONCLUSIONS: The present study, indicating the ratio above, offers a safety marker in order to realistically estimate the dose absorbed by interventional cardiologists, suggesting a specified number of permitted procedures and an effective level of radiation use protection tools.

Right ventricular involvement in coronary artery disease: role of echocardiography for diagnosis and prognosis.

The right ventricle differs from the left ventricle in many anatomic and physiologic aspects. This disparity renders the right ventricle less vulnerable to ischemia and less susceptible to myocardial injury when right coronary artery occlusion occurs compared with the extent of left ventricular dysfunction during left coronary artery occlusion. Acute right ventricular (RV) myocardial infarction is usually caused by proximal right coronary artery occlusion and therefore is usually associated with inferior myocardial infarction. Conventional echocardiography along with Doppler tissue imaging has played a significant role in early diagnosis of RV myocardial infarction and has a role in prognostic stratification. Stress echocardiography is less validated and more technically demanding in detecting RV reversible dysfunction compared with left ventricular dysfunction. The threshold of RV ischemia during stress echocardiography is higher compared with left ventricular ischemia and usually affects the inferior RV wall. Further studies, particularly with the use of novel echocardiographic techniques such as speckle-tracking and three-dimensional echocardiography, may be required to better elucidate the role of the right ventricle in coronary artery disease.