Use of combined cutting balloon and high-pressure balloon technique for the treatment of double-chambered right ventricle or primary infundibular stenosis: a case series

Five dogs and two cats with a diagnosis of double-chambered right ventricle or primary infundibular stenosis were referred to undergo a combined cutting balloon and high-pressure balloon technique. At admission five cases were asymptomatic, one had a history of syncope and one had signs of right-sided congestive heart failure. Each patient underwent a complete transthoracic echocardiogram, thoracic radiographs, an angiogram and the combined interventional procedure. Median diameter of the right mid-ventricular stenosis was 4 mm (range 2-8.7 mm) in dogs, and it measured 1.9 and 2 mm in cats. Under general anesthesia initial dilation with an 8-mm × 2-cm cutting balloon was performed from a left external jugular vein approach followed by dilation with a high-pressure balloon (1.5:1 balloon diameter-right outflow tract diameter ratio). In one dog and the two cats the procedure was not completed due to technical issues. In the other four dogs the median intracavitary proximal chamber pressure decreased from 100 mmHg (range 70-150 mmHg) before the procedure to 57 mmHg (range 45-70 mmHg) post-dilation. Long-term follow-up (from six months to two years) showed complete or partial reverse remodeling of the proximal chamber with a median residual pressure gradient below 80 mmHg (range 46-75 mmHg) for all four dogs. This case series shows that this procedure should be considered in dogs with right ventricular outflow tract obstruction. In cats, the procedure might be feasible, if additional guidewire inventory were available.

Electrocardiographic features of 431 consecutive, critically ill COVID-19 patients: an insight into the mechanisms of cardiac involvement

AIMS

Our aim was to describe the electrocardiographic features of critical COVID-19 patients.

METHODS AND RESULTS

We carried out a multicentric, cross-sectional, retrospective analysis of 431 consecutive COVID-19 patients hospitalized between 10 March and 14 April 2020 who died or were treated with invasive mechanical ventilation. This project is registered on ClinicalTrials.gov (identifier: NCT04367129). Standard ECG was recorded at hospital admission. ECG was abnormal in 93% of the patients. Atrial fibrillation/flutter was detected in 22% of the patients. ECG signs suggesting acute right ventricular pressure overload (RVPO) were detected in 30% of the patients. In particular, 43 (10%) patients had the S1Q3T3 pattern, 38 (9%) had incomplete right bundle branch block (RBBB), and 49 (11%) had complete RBBB. ECG signs of acute RVPO were not statistically different between patients with (n = 104) or without (n=327) invasive mechanical ventilation during ECG recording (36% vs. 28%, P = 0.10). Non-specific repolarization abnormalities and low QRS voltage in peripheral leads were present in 176 (41%) and 23 (5%), respectively. In four patients showing ST-segment elevation, acute myocardial infarction was confirmed with coronary angiography. No ST-T abnormalities suggestive of acute myocarditis were detected. In the subgroup of 110 patients where high-sensitivity troponin I was available, ECG features were not statistically different when stratified for above or below the 5 times upper reference limit value.

CONCLUSIONS

The ECG is abnormal in almost all critically ill COVID-19 patients and shows a large spectrum of abnormalities, with signs of acute RVPO in 30% of the patients. Rapid and simple identification of these cases with ECG at hospital admission can facilitate classification of the patients and provide pathophysiological insights.

Evaluation of thrombolytic treatment effect on frontal plane QRS-T angle in patients with acute pulmonary embolism : A novel marker of successful thrombolysis

BACKGROUND

Acute pulmonary embolism (APE) patients with hypotension and/or shock should be evaluated for thrombolytic therapy, and hemodynamics often improves after thrombolytic therapy. Frontal plane QRS‑T (f[QRS-T]) angle, which is between the directions QRS axis and T axis, was described as a novel marker of ventricular repolarization heterogeneity. With right ventricular pressure overload, axis of heart may be affected and thrombolytic treatment may have an effect on this situation. This study aimed to investigate thrombolytic efficiency and effect on axis of heart by using f(QRS-T) angle.

METHOD

A total of 61 APE patients treated with thrombolytics and 71 APE patients treated without thrombolytics were included. Clinical findings and electrocardiogram (ECG) at diagnosis were collected. Second ECGs were included for patients with thrombolytics after 24 h, without thrombolytics after 72 h on average.

RESULTS

No significant differences were observed with regard to gender, age, hypertension, diabetes and cardiovascular disease. In patients with thrombolytics, respiratory rate, heart rate and pulmonary artery systolic pressure were significantly higher; oxygen saturation (Sat O₂) as well as systolic and diastolic pressure were significantly lower. f(QRS-T) was markedly higher in APE with right ventricular pressure overload and changed significantly after thrombolytic therapy.

CONCLUSION

Right ventricular pressure overload in APE has an effect on f(QRS-T). In thrombolytic treatment, the change of f(QRS-T) angle may be a marker of successful thrombolysis.

Histologic and Hemodynamic Correlates of Right Ventricular Function in a Pressure Overload Model: a Study Using Three-Dimensional Speckle Tracking Echocardiography

The aim of our study was to assess the characterization of right ventricular (RV) deformation using three-dimensional (3D) speckle tracking echocardiography (STE) and association of 3D-STE indices with histologic and hemodynamic parameters in a chronic RV pressure overload animal model. Pulmonary artery banding (PAB) was used to induce RV pressure overload in seven beagles. 3D-STE, histologic and hemodynamic measurements were performed in PAB and sham-operated beagles 3 mo after PAB. RV longitudinal, radial and circumferential strain was measured from 3D-STE. Three mo after PAB, RV longitudinal strain was decreased; whereas radial and circumferential strain remained unchanged in PAB group. RV longitudinal strain was associated with interstitial fibrosis (r = -0.733) in the endocardial layer of the RV free wall. RV circumferential strain was related to dp/dt_max (r = 0.718). The significant correlations of RV 3D-STE indices with histologic and hemodynamic parameters indicate that 3D-STE may be a valuable tool for assessment of ventricular function in RV pressure overload.

Electrocardiographic detection of pulmonary hypertension in patients with systemic sclerosis using the ventricular gradient

BACKGROUND

Pulmonary hypertension (PH) is a leading cause of death in systemic sclerosis (SSc) patients. The current study assessed the ability of the ECG-derived ventricular gradient (VG-RVPO) to detect PH and predict all-cause mortality in PH patients with subtypes of SSc differing in the extent of multi-organ involvement.

METHODS

ECGs were obtained from 196 patients with limited and 77 patients with diffuse SSc included from our screening programme on cardiac complications. The association of the VG-RVPO with (1) the presence of PH, (2) conventional screening parameters and (3) survival in PH patients was assessed.

RESULTS

In limited SSc patients an elevated VG-RVPO corresponded with the presence of PH (-5±12 mV.ms vs -22±16 mV.ms, P<0.01), correlated significantly with conventional screening parameters and had a better diagnostic performance than the presence of a right heart axis (AUC 0.81 vs 0.60; P=0.04). These differences were not observed in patients with diffuse SSc. An elevated VG-RVPO was associated with decreased survival in all SSc patients with PH (3 year survival 30% vs 64%, P=0.02).

CONCLUSION

An elevated VG-RVPO is associated with PH in limited SSc patients and with decreased survival in all SSc patients with PH.

Effects of biventricular pacing on left heart twist and strain in a porcine model of right heart failure

BACKGROUND

Biventricular pacing (BiVP) improves cardiac output (CO) in selected cardiac surgery patients, but response remains variable, necessitating a better understanding of the mechanism. Accordingly, we used speckle tracking echocardiography (STE) to analyze BiVP during acute right ventricular pressure overload (RVPO).

MATERIALS AND METHODS

In nine pigs, the inferior vena cava (IVC) was snared to decrease CO and establish a control model. Heart block was induced, the pulmonary artery snared, and BiVP initiated. Echocardiograms of the left ventricular midpapillary level were taken at varying atrioventricular delay (AVD) and interventricular delay (VVD) for STE analysis of regional circumferential strain (CS) and radial strain (RS). Echocardiograms were taken of the left ventricular base, midpapillary, and apex during baseline, IVC occlusion, and each BiVP setting for STE analysis of twist, apical and basal rotations, CS, RS, and synchrony. Indices were correlated against CO with mixed linear models.

RESULTS

During IVC occlusion, CO correlated with twist, apical rotation, RS, RS synchrony, and CS (P < 0.05). During RVPO with BiVP, CO only correlated with RS synchrony and CS (P < 0.05). During AVD and VVD variations, CO was associated with free wall RS (P < 0.008). CO correlated with septal wall CS during AVD variation and free wall CS during VVD variation (P < 0.008).

CONCLUSIONS

In an open chest model, twist, RS, RS synchrony, and CS analyzed by STE may be noninvasive surrogates for changes in CO. During RVPO, changes in RS synchrony and CS with varying regional strain contributions may be the primary mechanism in which BiVP improves CO. Lack of correlation of remaining indices may reflect postsystolic function.