Vasodilator Strain Stress Echocardiography in Suspected Coronary Microvascular Angina.

Background: In patients with Ischemia and non-obstructive coronary artery stenosis (INOCA) wall motion is rarely abnormal during stress echocardiography (SE). Our aim was to determine if patients with INOCA and reduced coronary flow velocity reserve (CVFR) have altered cardiac mechanics using two-dimensional speckle-tracking echocardiography (2DSTE) during SE. Methods: In a prospective, multicenter, international study, we recruited 135 patients with INOCA. Overall, we performed high dose (0.84 mg/kg) dipyridamole SE with combined assessment of CVFR and 2DSTE. The population was divided in patients with normal CVFR (>2, group 1, n = 95) and abnormal CVFR (≤2, group 2, n = 35). Clinical and 2DSTE parameters were compared between groups. Results: Feasibility was high for CFVR (98%) and 2DSTE (97%). A total of 130 patients (mean age 63 ± 12 years, 67 women) had complete flow and strain data. The two groups showed similar 2DSTE values at rest. At peak SE, Group 1 patients showed lower global longitudinal strain (p < 0.007), higher mechanical dispersion (p < 0.0005), lower endocardial (p < 0.001), and epicardial (p < 0.0002) layer specific strain. Conclusions: In patients with INOCA, vasodilator SE with simultaneous assessment of CFVR and strain is highly feasible. Coronary microvascular dysfunction is accompanied by an impairment of global and layer-specific deformation indices during stress.

Coronary Flow, Left Ventricular Contractile and Heart Rate Reserve in Non-Ischemic Heart Failure.

Background: Left ventricular contractile reserve (LVCR), coronary flow velocity reserve (CFVR), and heart rate reserve (HRR) affect outcome in heart failure (HF). They can be simultaneously measured during dipyridamole stress echocardiography (DSE). Aim: To assess the value of comprehensive DSE in patients with non-ischemic HF. Methods: We evaluated 610 patients with HF, no history of coronary artery disease, and no inducible regional wall motion abnormalities: 270 patients with preserved ejection fraction (≥50%), 146 patients with mid-range ejection fraction (40-49%), and 194 patients with reduced ejection fraction (<40%). All underwent DSE (0.84 mg/kg in 6') in 7 accredited laboratories. We measured LVCR (abnormal value ≤ 1.1), CFVR in left anterior descending artery (abnormal value: ≤2.0), and HRR (peak/rest heart rate; abnormal value: ≤1.22). All patients were followed up. Results: Abnormal CFVR, LVCR, and HRR occurred in 29%, 45%, and 47% of patients, respectively (p < 0.001). After a median follow-up time of 20 months (interquartile range: 12-32 months), 113 hard events occurred in 105 patients with 41 deaths, 8 myocardial infarctions, 61 admissions for acute HF, and 3 strokes. The annual mortality rates were 0.8% in 200 patients with none abnormal criteria, 1.8% in 184 patients with 1 abnormal criterion, 7.1% in 130 patients with 2 abnormal criteria, 7.5% in 96 patients with 3 abnormal criteria. Conclusions: Abnormal LVCR, CFVR, and HRR were frequent during DSE in non-ischemic HF patients. They target different pathophysiological vulnerabilities (myocardial function, coronary microcirculation, and cardiac autonomic balance) and are useful for outcome prediction.

Feasibility and functional correlates of left atrial volume changes during stress echocardiography in chronic coronary syndromes.

An enlarged left atrial volume index (LAVI) at rest mirrors increased LA pressure and/or impairment of LA function. A cardiovascular stress may acutely modify left atrial volume (LAV) within minutes. Aim of this study was to assess the feasibility and functional correlates of LAV-stress echocardiography (SE) Out of 514 subjects referred to 10 quality-controlled labs, LAV-SE was completed in 490 (359 male, age 67 ± 12 years) with suspected or known chronic coronary syndromes (n = 462) or asymptomatic controls (n = 28). The utilized stress was exercise in 177, vasodilator in 167, dobutamine in 146. LAV was measured with the biplane disk summation method. SE was performed with the ABCDE protocol. The intra-observer and inter-observer LAV variability were 5% and 8%, respectively. ∆-LAVI changes (stress-rest) were negatively correlated with resting LAVI (r = - 0.271, p < 0.001) and heart rate reserve (r = -.239, p < 0.001). LAV-dilators were defined as those with stress-rest increase ≥ 6.8 ml/m2, a cutoff derived from a calculated reference change value above the biological, analytical and observer variability of LAVI. LAV dilation occurred in 56 patients (11%), more frequently with exercise (16%) and dipyridamole (13%) compared to dobutamine (4%, p < 0.01). At multivariable logistic regression analysis, B-lines ≥ 2 (OR: 2.586, 95% CI = 1.1293-5.169, p = 0.007) and abnormal contractile reserve (OR: 2.207, 95% CI = 1.111-4.386, p = 0.024) were associated with LAV dilation. In conclusion, LAV-SE is feasible with high success rate and low variability in patients with chronic coronary syndromes. LAV dilation is more likely with reduced left ventricular contractile reserve and pulmonary congestion.

[Long QRS tachycardia secondary to Aconitum napellus alkaloid ingestion]. / Tachicardia a QRS largo da ingestione alimentare di alcaloidi di Aconitum napellus.

The roots and seeds of the aconite (Aconitum napellus) contain alkaloids with modulatory activity on the sodium voltage-dependent channels; most fatal cases have been determined by ventricular tachycardia and respiratory paralysis. The only established treatment is supportive. We report a case of poisoning from Aconitum napellus, ingested by a husband and wife who thought the plant was "mountain chicory". They both had tachyarrhythmias, but the husband had more malignant episodes of hemodynamically unstable wide QRS tachycardia and respiratory paralysis requiring mechanical ventilation.