Right ventricular time intervals - Comparison between pulsed wave Doppler and tissue Doppler imaging.

BACKGROUND: Cardiac time intervals are used as indices of systolic and diastolic function. Echocardiographic assessment of these intervals is based on either pulsed wave Doppler (PWD) or tissue Doppler imaging (TDI). We investigated the agreement between the two techniques in the evaluation of right ventricular (RV) time intervals in healthy adults. METHODS: In 123 healthy volunteers we used both PWD and TDI to assess RV time intervals (filling time - RVFT, ejection time - RVET), heart rate-corrected intervals (total filling time - t-FT, total ejection time - t-ET) and RV performance indices (total isovolumic time - t-IVT, myocardial performance index - MPI). Intraclass correlation coefficient (ICC) and Pearson analysis (r coefficient) were used to evaluate the agreement and correlation between the two techniques. RESULTS: PWD and TDI had excellent agreement and correlation in measuring RVFT (ICC 0.94 [95% CI 0.85 - 0.97], r 0.91) whereas a good agreement was found for RVET (ICC 0.63[95% CI - 0.14 - 0.84]; r 0.68). Good agreement and strong correlation were found for both t-FT (ICC 0.67 [95% CI 0.36 - 0.82]; r 0.59) and t-ET (ICC 0.71 [95% CI - 0.06-0.88]; r 0.74). The two methods had lower agreement in assessing RV t-IVT (ICC 0.52 [95% CI 0.3187-0.6622]; r 0.57) and MPI (ICC 0.36 [95% CI - 0.05-0.43]; r 0.50). CONCLUSION: In healthy adults, PWD and TDI are interchangeable in measuring RVFT, RVET, RV t-FT and RV t-ET. Lower agreement between the two techniques was found for RV t-IVT and MPI.

Correction to: Inhaled nitric oxide in patients admitted to intensive care unit with COVID-19 pneumonia.

An amendment to this paper has been published and can be accessed via the original article.

Correlation Between Echocardiographic and Hemodynamic Variables in Cardiothoracic Intensive Care Unit.

OBJECTIVES: The echocardiographic indices have not been validated in critically ill population. The authors investigated the correlation between some echocardiographic and hemodynamic parameters. DESIGN: Prospective, spontaneous, noninterventional observational study. SETTING: Adult cardiothoracic intensive care unit, single center (Royal Brompton Hospital, London, United Kingdom). PARTICIPANTS: Consecutive adult patients admitted to the cardiothoracic intensive care unit for severe respiratory failure, primary cardiocirculatory failure, and post-aortic surgery. INTERVENTIONS: Clinical hemodynamic parameters (stroke volume [SV], cardiac output [CO], mean arterial pressure [MAP], and cardiac power index [CPI]) and echocardiographic indices of ventricular function (left ventricular total isovolumic time [t-IVT], mitral annular plane systolic excursion [MAPSE], and left ventricular fraction [LVEF]) were evaluated offline. MEASUREMENTS AND MAIN RESULTS: The study comprised 117 patients (age 57.2 ± 19; 60.6% male). The t-IVT showed an inverse correlation with SV, CO, MAP, and CPI (r -67%; -38%; -45%; -51%, respectively). MAPSE exhibited a positive correlation with SV, CO, MAP, and CPI (r 43%; 44%; 34%; 31%, respectively). LVEF did not show any correlation. In the multivariate analysis the association between t-IVT and hemodynamics was confirmed for SV, CO, MAP, and CPI, with the highest partial correlation between t-IVT and MAP (R = -58%). CONCLUSIONS: MAPSE and t-IVT are 2 reproducible and reliable echocardiographic indices of systolic function and ventricular efficacy associated with hemodynamic variables in cardiothoracic critically ill patients, whereas LVEF did not show any correlation.

Echocardiographic assessment of right ventricular performance in COVID-19 related acute respiratory distress syndrome: the importance of systo-diastolic interaction.

BACKGROUND: The cardiac manifestations of COVID-19 have been described in patients with acute respiratory distress syndrome (ARDS) admitted to intensive care unit (ICU). The presence and impact of right ventricular (RV) diastolic function and performance has not been studied in this population yet. We describe the prevalence of RV diastolic dysfunction, assessed by the pulmonary valve pre-ejection A wave (PV A wave), and the RV systo-diastolic interaction, using the RV total isovolumic time (t-IVT), in COVID-19 ARDS. RESULTS: Prospective observational study enrolling patients with moderate to severe COVID-19 ARDS admitted to ICU who underwent a transthoracic echocardiogram within 24 h of ICU admission and at least a second one during the ICU stay. Respiratory, hemodynamic and biochemistry parameters were collected. 163 patients (age 61.0 ± 9.3 years, 72% males) were enrolled. 36 patients (22.1%) had RV dysfunction, 45 (27.1%) LV systolic dysfunction. 73 patients (44.7%) had PV A wave. The RV t-IVT correlated with TAPSE at ICU admission (p < 0.002; r - 0.61), presence of PV A wave (p < 0.001; r 0.78), peak inspiratory pressure (PIP) (p < 0.001; r 0.42), PEEP (p < 0.001; r 0.68), dynamic driving pressure (DDP) (p < 0.001; r 0.58), and PaO2/FiO2 ratio (p < 0.01; r - 0.35). The presence of PV A wave was associated with higher PIP (p < 0.001; r 0.45), higher PEEP (p < 0.001; r 0.56), higher DDP (p < 0.01, r 0.51), and lower PaO2/FiO2 ratio (p < 0.001; r - 0.49). CONCLUSIONS: RV t-IVT and the presence of PV A wave are non-invasive means to describe a significant RV diastolic dysfunction and may be consider descriptive signs of RV performance in COVID-19 ARDS.

Endogenous Catecholamine Release in COVID-19 Related Acute Respiratory Distress Syndrome: Link between Enhanced Sympathetic Stimulation, Cardiac Dysfunction and Outcome.

The aim of this study was to measure the serum levels of catecholamines in patients admitted to intensive care unit (ICU) with COVID-19-related acute respiratory distress syndrome (ARDS) and describe their relation with clinical, inflammatory and echocardiographic parameters. Serum levels of endogenous catecholamines (norepinephrine, epinephrine and dopamine) were measured at ICU admission. We enrolled 71 patients consecutively admitted to ICU due to moderate to severe ARDS. 11 patients (15.5%) died during the admission in ICU. Serum levels of endogenous catecholamines were significantly elevated. Norepinephrine levels were higher in those with RV and LV systolic dysfunction, higher CRP, and higher IL-6. Patients with higher mortality rate were those with norepinephrine values ≥ 3124 ng/mL, CRP ≥ 17.2 mg/dL and IL-6 ≥ 102 pg/mL. Univariable analysis by Cox proportional hazards regression modelling showed that norepinephrine, IL-6 and CRP had the highest risk of acute mortality. Multivariable analysis showed that only norepinephrine and IL-6 retained in the model. Marked increase of serum catecholamine levels is present during acute phase of critically ill COVID-19 and it is associated with inflammatory and clinical parameters.

Heart rate control and haemodynamic improvement with ivabradine in cardiogenic shock patient on mechanical circulatory support.

AIMS: Cardiogenic shock (CS) is a life-threatening condition due to primary cardiac dysfunction. First-line therapy involves drug administration (including inotropes and/or vasopressors) up to mechanical circulatory support. Tachycardia is a frequent compensatory mechanism in response to hypotension and low cardiac output or a side effect related to inotropic drugs. Ivabradine selectively acts on the IKf channel in the sinoatrial node to reduce sinus heart rate without affecting inotropism. Its use, in small non-randomized series of patients with CS without mechanical circulatory support, was safe and well tolerated. METHODS AND RESULTS: We present the use of ivabradine in six patients with CS undertaking veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and a matched cohort of selected patients with similar features who did not receive ivabradine. Data regarding haemodynamic and echocardiographic monitoring, oxygenation, renal function, mechanical circulatory support, inotropes, and vasopressors doses were collected before (t0), at 12 (t1), 24 (t2), and 48 (t3) h after ivabradine administration. Ivabradine administration led to a significant heart rate reduction of 20.83 [95% confidence interval (CI) -27.2 to -14.4] b.p.m. (<0.01). Echo-derived left ventricular native stroke volume (SV) significantly increased by +7.83 (95% CI 4.74-10.93) mL (P < 0.001) with a parallel reduction of VA-ECMO support [-170 (95% CI -225.05 to -114.95)]. Noradrenaline was down-titrated over the observation period in all patients (P = 0.016). CONCLUSION: A significant reduction in heart rate was observed after ivabradine administration. This was associated with a native ventricular SV improvement allowing the reduction of extracorporeal flow support and vasopressors administration.

Pulmonary artery acceleration time accuracy for systolic pulmonary artery pressure estimation in critically ill patients.

BACKGROUND: Estimation of pulmonary pressures is of key importance in acute cardiovascular and respiratory failure. Pulmonary artery acceleration time (PAAT) has emerged as reliable parameter for the estimation of systolic pulmonary artery pressure (sPAP) in cardiological population with preserved right ventricular function. We sought to find whether PAAT correlates with sPAP in critically ill patients with and without right ventricular (RV) systolic dysfunction. METHODS: Observational study. We measured sPAP using continuous-wave Doppler analysis of tricuspid regurgitation velocity peak method and we assessed the validity of PAAT in estimating sPAP in patients admitted to adult intensive care unit (ICU) for acute cardiovascular and respiratory failure. RESULTS: We enrolled 236 patients admitted to cardiothoracic ICU for cardiovascular and respiratory failure (respectively: 129, 54.7% and 107, 45.3%). 114 (48.3%) had preserved RV systolic function (defined as TAPSE ≥ 17 mm), whilst 122 (51.7%) had RV systolic impairment (defined as TAPSE < 17 mm). A weak inverse correlation between PAAT and sPAP (ρ-0.189, p 0.0035) was observed in overall population, which was confirmed in those with preserved RV systolic PAAT and sPAP (ρ-0.361, p 0.0001). In patients with impaired RV systolic function no statistically significant correlation between PAAT and sPAP was demonstrated (p 0.2737). Adjusting PAAT values for log10, heart rate and RV ejection time did not modify the abovementioned correlations. CONCLUSIONS: PAAT measurement to derive sPAP is not reliable in cardiothoracic critically ill patients, particularly in the coexistence of RV systolic impairment.

Mechanical circulatory support in ventricular arrhythmias.

In atrial and ventricular tachyarrhythmias, reduced time for ventricular filling and loss of atrial contribution lead to a significant reduction in cardiac output, resulting in cardiogenic shock. This may also occur during catheter ablation in 11% of overall procedures and is associated with increased mortality. Managing cardiogenic shock and (supra) ventricular arrhythmias is particularly challenging. Inotropic support may exacerbate tachyarrhythmias or accelerate heart rate; antiarrhythmic drugs often come with negative inotropic effects, and electrical reconversions may risk worsening circulatory failure or even cardiac arrest. The drop in native cardiac output during an arrhythmic storm can be partly covered by the insertion of percutaneous mechanical circulatory support (MCS) devices guaranteeing end-organ perfusion. This provides physicians a time window of stability to investigate the underlying cause of arrhythmia and allow proper therapeutic interventions (e.g., percutaneous coronary intervention and catheter ablation). Temporary MCS can be used in the case of overt hemodynamic decompensation or as a "preemptive strategy" to avoid circulatory instability during interventional cardiology procedures in high-risk patients. Despite the increasing use of MCS in cardiogenic shock and during catheter ablation procedures, the recommendation level is still low, considering the lack of large observational studies and randomized clinical trials. Therefore, the evidence on the timing and the kinds of MCS devices has also scarcely been investigated. In the current review, we discuss the available evidence in the literature and gaps in knowledge on the use of MCS devices in the setting of ventricular arrhythmias and arrhythmic storms, including a specific focus on pathophysiology and related therapies.