Pathophysiological and clinical implications of high intramural coronary blood flow velocity in aortic stenosis.

We sought to recognize the blood flow velocity (BFV) through the left anterior descending (LAD) coronary artery and its small intramyocardial (IM) branches by transthoracic Doppler-echocardiography in patients with aortic stenosis (AS). Sixty-two patients, aged 74.0 ± 9.6 years, 37 women, with preserved left ventricular (LV) function, apparently free of active ischemic disease, were enrolled and classified into 3 groups according to the mean gradient (MG) across the aortic valve: 13 patients (21%) entered the group A (MG ≤ 20 mmHg), 29 (48%) group B (MG 21-40 mmHg) and 20 (31%) group C (MG > 40 mmHg). Peak and mean coronary BFVs were demonstrated to gradually increase according to AV gradient, especially through the IM arteries. Peak IM-BFV was 58.9 cm/s (95% CI 46.4-71.4) in group A, 73.2 cm/s (95% CI 64.8-81.6) in group B, and 96.4 cm/s (95% CI 86.3-106.5) in group C (p < 0.001), whereas peak LAD-BFV was 38.1 cm/s (95% CI 32.8-43.3), 44.4 cm/s (95% CI 40.9-47.9) and 47.3 cm/s (95% CI 43.1-52.5), respectively (p = 0.03). Also, 34 patients complaining with unspecific symptoms showed much higher IM-BFV than those who were not. High values were also recognized in patients with LV ejection fraction/velocity ratio (EFVR) ≤ 0.90 (IM-BFV 91 ± 26 cm/s vs. 72 ± 24 cm/s in those with EFVR > 0.90, p = 0.001). In conclusion, AS patients in the present study showed gradually higher coronary BFVs according to AS gradient, especially through the IM vessels, and both peak and mean velocities were discriminating specific patient subsets. Pathophysiological mechanisms and potential clinical implications are discussed.

Extrinsic pulmonary stenosis in primary mediastinal B-cellular lymphoma.

We describe the case of a 34-year-old man with a history of asthenia and excessive fatigability. Transthoracic echocardiography showed a mass in the right ventricular outflow tract with a peak systolic gradient of 52 mmHg. Contrast-enhanced CT confirmed the presence of a lobulated mass, which extensively filled the anterior mediastinum, infiltrating the pulmonary artery trunk up to occupying the right ventricular outflow tract. CT-guided biopsy revealed primary mediastinal B-cellular lymphoma. The patient underwent chemotherapy, achieving complete remission of the disease at the 12-month follow-up, while the gradient across the pulmonary artery dropped from 52 mmHg to 14 mmHg.

Transient Left Ventricular Dysfunction from Cardiomyopathies to Myocardial Viability: When and Why Cardiac Function Recovers.

Transient left ventricular dysfunction (TLVD), a temporary condition marked by reversible impairment of ventricular function, remains an underdiagnosed yet significant contributor to morbidity and mortality in clinical practice. Unlike the well-explored atherosclerotic disease of the epicardial coronary arteries, the diverse etiologies of TLVD require greater attention for proper diagnosis and management. The spectrum of disorders associated with TLVD includes stress-induced cardiomyopathy, central nervous system injuries, histaminergic syndromes, various inflammatory diseases, pregnancy-related conditions, and genetically determined syndromes. Furthermore, myocardial infarction with non-obstructive coronary arteries (MINOCA) origins such as coronary artery spasm, coronary thromboembolism, and spontaneous coronary artery dissection (SCAD) may also manifest as TLVD, eventually showing recovery. This review highlights the range of ischemic and non-ischemic clinical situations that lead to TLVD, gathering conditions like Tako-Tsubo Syndrome (TTS), Kounis syndrome (KS), Myocarditis, Peripartum Cardiomyopathy (PPCM), and Tachycardia-induced cardiomyopathy (TIC). Differentiation amongst these causes is crucial, as they involve distinct clinical, instrumental, and genetic predictors that bode different outcomes and recovery potential for left ventricular function. The purpose of this review is to improve everyday clinical approaches to treating these diseases by providing an extensive survey of conditions linked with TLVD and the elements impacting prognosis and outcomes.

Cardiac Magnetic Resonance in HCM Phenocopies: From Diagnosis to Risk Stratification and Therapeutic Management.

Hypertrophic cardiomyopathy (HCM) is a genetic heart disease characterized by the thickening of the heart muscle, which can lead to symptoms such as chest pain, shortness of breath, and an increased risk of sudden cardiac death. However, not all patients with HCM have the same underlying genetic mutations, and some have conditions that resemble HCM but have different genetic or pathophysiological mechanisms, referred to as phenocopies. Cardiac magnetic resonance (CMR) imaging has emerged as a powerful tool for the non-invasive assessment of HCM and its phenocopies. CMR can accurately quantify the extent and distribution of hypertrophy, assess the presence and severity of myocardial fibrosis, and detect associated abnormalities. In the context of phenocopies, CMR can aid in the differentiation between HCM and other diseases that present with HCM-like features, such as cardiac amyloidosis (CA), Anderson-Fabry disease (AFD), and mitochondrial cardiomyopathies. CMR can provide important diagnostic and prognostic information that can guide clinical decision-making and management strategies. This review aims to describe the available evidence of the role of CMR in the assessment of hypertrophic phenotype and its diagnostic and prognostic implications.

Evidence of cardiovascular autonomic impairment in mitochondrial disorders.

OBJECTIVE: To investigate autonomic nervous system (ANS) function in mitochondrial disorders (MD). BACKGROUND: MD are characterized by a wide range of clinical features, including heart abnormalities and peripheral and central nervous systems involvement. Rarely autonomic symptoms have been reported. METHODS: 22 patients with MD underwent a battery of cardiovascular reflex tests including five tests of parasympathetic function and four tests of sympathetic function. Power spectral analyses (PSA) of heart rate variability in the supine and upright positions were also evaluated. Plasma levels of adrenaline, noradrenaline and dopamine were determined in the standing and lying positions. RESULTS: Only 4/22 patients referred symptoms related to ANS dysfunction. 46% of patients had a definite autonomic damage (i. e. an autonomic score >/= 4). 36% showed moderate alterations with an autonomic score in the range 2-3 and 18 % had a normal autonomic function. MD patients had a significantly (p <0.03) lower increase of adrenaline level after standing. CONCLUSIONS: Our data indicate an autonomic dysfunction in more than 80% of MD patients, even in the absence of a clinically manifested autonomic involvement. Cardiovascular autonomic investigation might be systematically employed in the characterization of MD.

Echocardiographic assessment of subclinical left ventricular eccentric hypertrophy in adult-onset GHD patients by geometric remodeling: an observational case-control study.

BACKGROUND: Most patients with growth hormone deficiency (GHD) show high body mass index. Overweight subjects, but GHD patients, were demonstrated to have high left ventricular mass index (LVMi) and abnormal LV geometric remodeling. We sought to study these characteristics in a group of GHD patients, in an attempt to establish the BMI-independent role of GHD. METHODS: Fifty-four patients, 28 F and 26 M, aged 45.9 +/- 13.1, with adult-onset GHD (pituitary adenomas 48.2%, empty sella 27.8%, pituitary inflammation 5.5%, cranio-pharyngioma 3.7%, not identified pathogenesis 14.8%) were enrolled. To minimize any possible interferences of BMI on the aim of this study, the control group included 20 age- and weight-matched healthy subjects. The LV geometry was identified by the relationship between LVMi (cut-off 125 g/m2) and relative wall thickness (cut-off 0.45) at echocardiography. RESULTS: There was no significant between-group difference in resting cardiac morphology and function, nor when considering age-related discrepancy. The majority of patients had normal-low LVM/LVMi, but about one fourth of them showed higher values. These findings correlated to relatively high circulating IGF-1 and systolic blood pressure at rest. The main LV geometric pattern was eccentric hypertrophy in 22% of GHD population (26% of with severe GHD) and in 15% of controls (p = NS). CONCLUSION: Though the lack of significant differences in resting LV morphology and function, about 25% of GHD patients showed high LVMi (consisting of eccentric hypertrophy), not dissimilarly to overweight controls. This finding, which prognostic role is well known in obese and hypertensive patients, is worthy to be investigated in GHD patients through wider controlled trials.

Behavior of both epicardial and intramural coronary artery flow velocities in various models of myocardial hypertrophy: role for left ventricular outflow tract obstruction.

BACKGROUND: The assessment of coronary flow velocity is becoming crucial in the diagnosis and management of several cardiac dysfunctions and conventional Doppler echocardiography is currently the technique most widely used for detecting their abnormalities noninvasively. METHODS: We sought to evaluate the differences in coronary flow velocity using conventional transthoracic Doppler echocardiography, measuring both the left anterior descending and such intramural (IM) coronary arteries' flow, among the following 4 categories of patients with myocardial hypertrophy: group A, obstructive hypertrophic cardiomyopathy (n = 12); group B, nonobstructive hypertrophic cardiomyopathy (n = 10); group C, left ventricular hypertrophy (LVH) due to hypertension (n = 10); and group D, LVH due to aortic valve stenosis (n = 10). RESULTS: No significant difference between the 4 groups was found with respect to the left anterior descending velocity. Diastolic peak (P < .01) and mean (P < .05) velocities in the IM arterioles were significantly higher in patients from groups A and D than in groups B and C. At multivariate analysis, both dynamic (group A) and fixed (group D) systolic peak gradients, measured by continuous wave Doppler sampling through the left ventricular (LV) outflow tract or the aortic valve, respectively, were found to be major determinants of the IM diastolic velocity, independently on the LV mass. About 75% of patients with obstructive hypertrophic cardiomyopathy showed IM peak and mean velocity >100 cm/s and >70 cm/s, respectively (P = .005). CONCLUSION: These findings likely suggest [corrected] a role for the LV systolic obstruction within the intricate adaptive mechanisms of coronary blood flow to LVH.

Noninvasive assessment of intramyocardial coronary flow in hypertrophic cardiomyopathy by high-resolution Doppler echocardiography.

Dyspnea and angina have been described in patients with hypertrophic cardiomyopathy (HCM). Given the complexity of the coronary microcirculation, the pathophysiological mechanisms of angina are discussed. The last generation of echo devices allows the investigation of epicardial coronary flow by means of the standard transthoracic approach (TTE). In the present study we describe 5 patients affected by HCM (with outflow tract dynamic obstruction in 2 cases, intraventricular dynamic obstruction in the other 2, no obstruction in the last one) in whom both the epicardial and intramyocardial coronary flows were assessed at high-resolution TTE. Regular flow velocities were shown in epicardial coronary arteries, while in intramyocardial branches the diastolic peak velocity was > 75 cm/s in all patients. Besides, the systolic flow was found to be inverted. Similar to what suggested by the few data presently available in the literature, the main findings of this study confirm the appropriateness of investigating the intramyocardial coronary circulation in patients with HCM by means of high-resolution Doppler echocardiography. In order to explain this clinical finding, an interesting hypothesis of a diastolic "milking-like" phenomenon associated with systolic "blood squeezing" in the intramural coronary arteries was taken into consideration. The noninvasive study of the intramyocardial coronary flow may be clinically relevant even in the evaluation of the effectiveness of the adopted therapeutic strategy in reducing myocardial wall stress in severe ventricular hypertrophy.

P-wave voltage and peaking on electrocardiogram in patients undergoing head-up tilt testing for history of syncope.

BACKGROUND: Only scanty data are available in the literature on P-wave (PW) morphology at ECG in patients with history of vasovagal syncope undergoing diagnostic functional testing. In this study, we evaluated resting and head-up tilt testing (HUTT) related changes in PW voltage (PWV) and duration (PVD) and their relationship with triggered syncope. METHODS: 55 patients, mean aged 41 ± 19 y (35 F), without patent heart disease or neuropathy, underwent potentiated HUTT according to the Italian protocol. Heart rate (HR), blood pressure (BP), PR-interval, PWV and PWD were measured at rest, 15 min from passive position (15-min) and after nitroglycerine (peak-HR). PW peaking (PWP) was calculated as percent increase in PWV than baseline values. Patients were divided into 2 groups based on tilt-positive (group-A) or negative (group-B) response. RESULTS: 20 patients (36%) entered the group-A, whereas 35 (64%) the group-B. Higher PWV was observed at baseline in group-A (0.147 ± 0.034 mV vs 0.114 ± 0.036 mV in group-B, p=0.001), with no differences in the remaining ECG measurements. BP was lower in group-A than in B, both at 15-min and peak-HR. HUTT-related PWP in lead II (the most significant among all inferior leads) was 31 ± 30% in group-A vs 95 ± 54% in group-B (p<0.0001) at 15-min, and 52 ± 44% vs 112±72% at peak-HR, respectively (p=0.002). 75% of patients with PWP ≤ 50% experienced HUTT-triggered syncope, vs 5% of those with PWP ≥ 100% (p<0.0001). CONCLUSIONS: This study shows a potential relationship between HUTT-triggered syncope and low or absent PWP, suggesting a role for atrial chamber functional involvement in the mechanisms underlying the vasovagal syncope.

Left ventricular thrombus formation and cardioembolic complications in patients with Takotsubo-like syndrome: a systematic review.

BACKGROUND: Though a severe left ventricular systolic dysfunction has been described in most patients with Takotsubo-like (or Apical Ballooning) syndrome, the occurrence of intra-cavitary thrombus formation seems to be such an exceptional finding. However, no large studies but single case descriptions of this complication are available over the last decade in the literature. METHODS: By searching for the PubMed-Medline database we selected 14 studies that met our eligibility criteria. RESULTS: Demographic, clinical and morphofunctional characteristics of 15 patients who where described to have left ventricular thrombosis as a complication of the Takotsubo-like syndrome are comprehensively described in this review. Cardioembolic complications (stroke in 3 cases, renal infarction or popliteal artery thrombosis in other two) occurred in 33.3% out of them. The incidence of thrombus formation and related systemic embolisms in the general population with this syndrome were established on the basis of such available historical data and reviews on this subject. CONCLUSION: Left ventricular thrombus formation has been reported in at least 14 studies (15 patients) over the last decade until the end of 2007. This approximately results in about 2.5% of all the patients with documented Takotsubo-like syndrome. Cardioembolic complications occurred in 5/15 cases, corresponding to 0.8% of the whole known population.

Can transthoracic live 3-dimensional echocardiography improve the recognition of midventricular obliteration in hypertrophic obstructive cardiomyopathy?

In this report the authors analyzed the usefulness of live 3-dimensional echocardiography in association with conventional 2-dimensional method to improve the recognition of left ventricular midcavitary obliteration in a patient with hypertrophic cardiomyopathy.