Left Ventricular Perfusion Research Articles

Myocardial perfusion single-photon emission computer tomography and coronary angiography results in patients with different pretest probability of ischemic heart disease

To study the relationship between pretest probability (PTP) of ischemic heart disease (IHD), calculated according to the recommendations of the European Society of Cardiology (ESC) of 2013 and 2019, with the perfusion of the left ventricle of the myocardium according to the single-photon emission tomography (SPECT) and the results of the invasive coronary angiography (CAG). The study included 220 patients with a preliminary diagnosis of ischemic heart disease and planned invasive CAG. All patients underwent rest-stress perfusion myocardial SPECT within 1 month prior to or after CAG, standard quantitative parameters of left ventricular perfusion were assessed. Retrospectively clinical data was analyzed and PTP of IHD was assessed according to ESC recommendations for 2013 and 2019. Invasive CAG revealed obstructive lesion of one or more coromary arteries in 204 of the 220 patients (92.7%). In a retrospective analysis, taking into account gender, age and nature of the complaints, as recommended by ESC in 2013, PTP was rated as low (15%) in 13 patients (5.9%), as intermediate (1585%) in 207 patients (94.1%). Following the comprehensive survey (SPECT and CAG) 8 patients with low PTP (61.5%) underwent coronary revascularization. Among patients with intermediate PTP significant transient ischemia according to SPECT was detected in 31 (15.0%), initial at 107 (51.7%). According CAG among patients with intermediate PTP obstructive lesion was found in 192 (92.7%), 113 patients (58.8%) underwent revascularization. According to ESC recommendations of 2019, PTP was rated as low (15%) in 117 patients (53.2%), including 514% in 98 (44.5%). According to a survey (SPECT and CAG) 68 of them (58.1%) underwent revascularization. PTP measurements proposed by ESC can not be applied to patients of the Russian population with suspected ischemic heart disease without significant corrections. 2013 ESC recommendations with higher PTP values for all categories of patients reflect Russian population better, while 2019 recommendations mistakenly attribute patients to low PTP in at least 58% of cases. These results are preliminary and will be expanded in subsequent studies with more detailed analysis of PTP in included patients with suspected IHD.

Contrast Echocardiography with a Quantitative Assessment of Myocardial Perfusion in Patients with Previous Q-Wave Myocardial Infarction

To assess possibilities of contrast echocardiography with quantitative evaluation of myocardial perfusion in patients with previous Q-wave myocardial infarction. We examined 15 men (42-72 years) with coronary artery disease and previous myocardial infarction, and pathological Q-wave in 2 or more ECG leads. Quantification of left ventricular (LV) myocardial perfusion was performed by calculating of the ultrasound signal tissue intensity from the LV myocardial segments during intravenous administration of the ultrasound contrast agent (SonoVue). The Tissue intensive curve (TIC) analysis was done in the end-diastolic period before and on the fourth cardiac cycle after applying the "flash". Changes in the intensity of myocardial perfusion (A4, dB) was estimated as the difference between the intensity values of the ultrasound signal in the myocardial segment during the period of filling the contrast bubbles on 4-th cardiac cycle and before applying the «flash». Measurements were performed in 16 segments of the LV. A contrast cardiac magnetic resonance imaging (contrast MRI) was performed in order to verify the LV scar. Fibrotic changes of 50% of myocardial wall or more were considered as signs of post-infarction scar. The dynamics of perfusion and scar presence in 240 myocardial segments were evaluated. The median A4 was 1 dB (range, -20 to 10 dB). MRI revealed 82 of 240 segments with the large-focal scar. The effectiveness of the diagnostic test (quantitative contrast perfusion echocardiography with A4 assessment) to detect myocardial scar was investigated. ROC curve analysis showed good model quality, AUC=0,787 (0,730-0,837); sensitivity 82.9%; specificity 75.3%; p<0.01. The cut-off point for A4 was -1. A new approach to quantitative contrast assessment of perfusion allows to identify perfusion disorders with high efficiency in patients with previous Q-wave myocardial infarction.

Development of a high-resolution and high-efficiency single-photon detector for studying cardiovascular diseases in mice

SPECT systems using pinhole apertures permit radiolabeled molecular distributions to be imaged in vivo in small animals. Nevertheless studying cardiovascular diseases by means of small animal models is very challenging. Specifically, submillimeter spatial resolution, good energy resolution and high sensitivity are required. We designed what we consider the "optimal" radionuclide detector system for this task. It should allow studying both detection of unstable atherosclerotic plaques and monitoring the effect of therapies. Using mice is particularly challenging in situations that require several intravenous injections of radiotracers, possibly for week or even months, in chronically ill animals. Thus, alternative routes of delivering the radiotracer in tail vein should be investigated. In this study we have performed preliminary measurements of detection of atherosclerotic plaques in genetically modified mice with high-resolution prototype detector. We have also evaluated the feasibility of assessing left ventricular perfusion by intraperitoneal delivering of MIBI-Tc in healthy mice.

Molecular and Cellular Mechanisms that Induce Arterial Calcification by Indoxyl Sulfate and P-Cresyl Sulfate.

The protein-bound uremic toxins, indoxyl sulfate (IS) and p-cresyl sulfate (PCS), are considered to be harmful vascular toxins. Arterial media calcification, or the deposition of calcium phosphate crystals in the arteries, contributes significantly to cardiovascular complications, including left ventricular hypertrophy, hypertension, and impaired coronary perfusion in the elderly and patients with chronic kidney disease (CKD) and diabetes. Recently, we reported that both IS and PCS trigger moderate to severe calcification in the aorta and peripheral vessels of CKD rats. This review describes the molecular and cellular mechanisms by which these uremic toxins induce arterial media calcification. A complex interplay between inflammation, coagulation, and lipid metabolism pathways, influenced by epigenetic factors, is crucial in IS/PCS-induced arterial media calcification. High levels of glucose are linked to these events, suggesting that a good balance between glucose and lipid levels might be important. On the cellular level, effects on endothelial cells, which act as the primary sensors of circulating pathological triggers, might be as important as those on vascular smooth muscle cells. Endothelial dysfunction, provoked by IS and PCS triggered oxidative stress, may be considered a key event in the onset and development of arterial media calcification. In this review a number of important outstanding questions such as the role of miRNA’s, phenotypic switching of both endothelial and vascular smooth muscle cells and new types of programmed cell death in arterial media calcification related to protein-bound uremic toxins are put forward and discussed.

Assessment of the Preventive Effect Against Diabetic Cardiomyopathy of FGF1-Loaded Nanoliposomes Combined With Microbubble Cavitation by Ultrasound

Acidic fibroblast growth factor (FGF1) has great potential in preventing diabetic cardiomyopathy. This study aimed to evaluate the preventive effect of FGF1-loaded nanoliposomes (FGF1-nlip) combined with ultrasound-targeted microbubble destruction (UTMD) on diabetic cardiomyopathy (DCM) using ultrasound examination. Nanoliposomes encapsulating FGF1 were prepared by reverse phase evaporation. DM model rats were established by intraperitoneal injection of streptozotocin (STZ), and different forms of FGF1 (FGF1 solution, FGF1-nlip, and FGF1-nlip+UTMD) were used for a 12-week intervention. According to the transthoracic echocardiography and velocity vector imaging (VVI) indexes, the LVEF, LVFS, and VVI indexes (Vs, Sr, SRr) in the FGF1-nlip+UTMD group were significantly higher than those in the DM model group and other FGF1 intervention groups. From the real-time myocardial contrast echocardiography (RT-MCE) indexes, the FGF1-nlip+UTMD group A and A×β showed significant differences from the DM model group and other FGF1 intervention groups. Cardiac catheter hemodynamic testing, CD31 immunohistochemical staining, and electron microscopy also confirmed the same conclusion. These results confirmed that the abnormalities, including myocardial dysfunction and perfusion impairment, could be suppressed to different extents by the twice weekly FGF1 treatments for 12 consecutive weeks (free FGF1, FGF1-nlip, and FGF1-nlip+UTMD), with the strongest improvements observed in the FGF1-nlip+UTMD group. In conclusion, the VVI and RT-MCE techniques can detect left ventricular systolic function and perfusion changes in DM rats, providing a more effective experimental basis for the early detection and treatment evaluation of DCM, which is of great significance for the prevention of DCM.

Useful assessment of myocardial viability and dyssynchrony from gated perfusion scintigraphy for better qualification for resynchronization therapy. Part 3.

The first part of the review concerning myocardial imaging by single photon emission computed tomography (SPECT) discussed the basic aspects of interpretation of left ventricular perfusion disorders in stress and rest examination. The second part presented the interpretation of gated SPECT imaging in relation to the assessment of systolic and diastolic left ventricular functions. The third part concerns the assessment of myocardial viability and phase analysis from gated SPECT in the qualification of patients with left ventricular systolic dysfunction for cardiac resynchronization therapy.

Sex-dependent association between inflammation, neural stress responses, and impaired myocardial function.

Evidence to date has failed to reveal unique female determinants of cardiovascular disease. However, a strong association was recently observed between increased metabolic activity in the amygdala, a neural centre involved in the processing of emotions, and impaired myocardial function in women, but not in men. Given the stronger immune responses in females, we sought to retrospectively investigate the interaction between inflammation, perceived stress, and myocardial injury. Overall, 294 patients (mean age 66.9 ± 10.0years, 28.6% women) underwent both, 99mTc-tetrofosmin single-photon emission computed tomography myocardial perfusion imaging and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography for the assessment of cardiac function, bone marrow metabolism (surrogate marker of inflammation), and resting amygdalar activity. A positive association was found between amygdalar metabolism and 18F-FDG bone marrow uptake in women (r = 0.238, p = 0.029), but not in men (r = 0.060, p = 0.385). Linear regression models selected both, abnormal left ventricular ejection fraction (LVEF) and abnormal myocardial perfusion, as significant indicators of an increased amygdalar activity in women (B-coefficient LVEF, - 0.096; p = 0.021; abnormal myocardial perfusion, 3.227; p = 0.043), but not in men (bone marrow p = 0.076; abnormal myocardial perfusion p = 0.420). Accordingly, an interaction term consisting of sex and LVEF/abnormal myocardial perfusion was significant (p = 0.043 and p = 0.015, respectively). Upregulated amygdalar metabolism is associated with an enhanced inflammatory state in female patients with impaired cardiac function. Given that enhanced activity of the limbic system is associated with worse cardiovascular outcomes, our study suggests that a focus on inflammatory markers and indicators of distress might help to tailor cardiovascular risk assessment and therapy towards the female cardiovascular phenotype.

Evaluation of computed tomography myocardial perfusion in women with angina and no obstructive coronary artery disease.

Women with angina and no obstructive coronary artery disease (CAD) have worse cardiovascular prognosis than asymptomatic women. Limitation in myocardial perfusion caused by coronary microvascular dysfunction (CMD) is one of the proposed mechanisms contributing to the adverse prognosis. The aim of this study was to assess myocardial perfusion in symptomatic women with no obstructive CAD suspected for CMD compared with asymptomatic sex-matched controls using static CT perfusion (CTP). We performed a semi-quantitative assessment of the left ventricular myocardial perfusion and myocardial perfusion reserve (MPR), using static CTP with adenosine provocation, in 105 female patients with angina and no obstructive CAD (< 50% stenosis) and 33 sex-matched controls without a history of angina or ischemic heart disease. Patients were on average 4years older (p = 0.04) and had a higher burden of cardiovascular risk factors. While global perfusion during rest was comparable between the groups (age-adjusted p = 0.12), global perfusion during hyperemia was significantly reduced in patients compared with controls (163 ± 23 HU vs. 171 ± 25 HU; age-adjusted p = 0.023). The ability to increase myocardial perfusion during adenosine-induced vasodilation was significantly diminished in patients (MPR 148% vs. 158%; age-adjusted p < 0.001). This remained unchanged after adjustment for cardiovascular risk factors (p = 0.008). Women with angina and no obstructive CAD have reduced hyperemic myocardial perfusion and MPR compared with sex-matched controls. Impaired myocardial perfusion may be related to the presence of CMD in some of these women.

Albumin Coating Prevents Cardiac Effect of the Magnetic Nanoparticles.

We have showed that surface layer can determine cardiac effects of the magnetic nanoparticles (MNPs). Considering the high binding capacity of albumin and low side-effects, the aim of this study was to evaluate the influence of albumin coating on the cardiovascular effects of two manganese ferrite-based MNPs: citrate-coated and bare MNPs. Isolated rat hearts were perfused with citrate-coated magnetic nanoparticles (CiMNPs), citrate albumin-coated magnetic nanoparticles (CiAlbMNPs), bare magnetic nanoparticles (BaMNPs), and albumin-coated magnetic nanoparticles (AlbMNPs). CiMNPs induce a transient decrease in the left ventricular end-systolic pressure, +dP/dt and -dP/dt. These effects were not worsened by albumin coating. BaMNPs significantly increased the left ventricular end-diastolic pressure and perfusion pressure and decreased the +dP/dt and -dP/dt. These effects were completely absent in hearts perfused with AlbMNPs. None of the MNPs changed heart rate or arterial blood pressure in conscious rats. Magnetic signals in isolated hearts perfused with BaMNPs were significantly higher than AlbMNPs perfused hearts. However, the magnetic signal in heart tissue was similar when the MNPs were infused in conscious rats. These data indicate that albumin-coated can reduce cardiovascular effects of MNPs. These findings suggest a protective effect of albumin surface in MNPs, favoring its future therapeutic applications.

Mechanical circulatory support with the Impella 5.0 and the Impella Left Direct pumps for postcardiotomy cardiogenic shock at La Pitié-Salpêtrière Hospital.

Postcardiotomy cardiogenic shock (PCCS) is associated with high mortality rates of 50-80%. Although veno-arterial extracorporeal membrane oxygenation has been used as mechanical circulatory support in patients with PCCS, it is associated with a high rate of complications and poor quality of life. The Impella 5.0 and Impella Left Direct (LD) (Impella 5.0/LD) are minimally invasive left ventricular assist devices that provide effective haemodynamic support resulting in left ventricular unloading and systemic perfusion. Our goal was to describe the outcome of patients with PCCS supported with the Impella 5.0/LD at La Pitié-Salpêtrière Hospital. We retrospectively reviewed consecutive patients supported with the Impella 5.0/LD for PCCS between December 2010 and June 2015. Survival outcome and in-hospital complications were assessed. A total of 29 patients (63 ± 14 years, 17% women) with PCCS were supported with the Impella 5.0/LD. At baseline, 69% experienced chronic heart failure, 66% had dilated cardiomyopathy and 57% had valvular disease. The mean EuroSCORE II was 22 ± 17 and the ejection fraction was 28 ± 11%. Most of the patients underwent isolated valve surgery (45%) or isolated coronary artery bypass grafting (38%). The mean duration of Impella support was 9 ± 7 days. Weaning from the Impella was successful in 72.4%, and 58.6% survived to discharge. Recovery of native heart function was observed in 100% of discharged patients. Survival to 30 days and to 1 year from Impella implant was 58.6% and 51.7%, respectively. The Impella 5.0 and the Impella LD represent an excellent treatment option for critically ill patients with PCCS and are associated with favourable survival outcome and native heart recovery.

Myocardial Injury After Ischemia/Reperfusion Is Attenuated By Pharmacological Galectin-3 Inhibition

Although optimal therapy for myocardial infarction includes reperfusion to restore blood flow to the ischemic region, ischemia/reperfusion (IR) also initiates an inflammatory response likely contributing to adverse left ventricular (LV) extracellular matrix (ECM) remodeling. Galectin-3 (Gal-3), a β-galactoside-binding-lectin, promotes cardiac remodeling and dysfunction. Our aim is to investigate whether Gal-3 pharmacological inhibition using modified citrus pectin (MCP) improves cardiac remodeling and functional changes associated with IR. Wistar rats were treated with MCP from 1 day before until 8 days after IR (coronary artery ligation) injury. Invasive hemodynamics revealed that both LV contractility and LV compliance were impaired in IR rats. LV compliance was improved by MCP treatment 8 days after IR. Cardiac magnetic resonance imaging showed decreased LV perfusion in IR rats, which was improved with MCP. There was no difference in LV hypertrophy in MCP-treated compared to untreated IR rats. However, MCP treatment decreased the ischemic area as well as Gal-3 expression. Gal-3 blockade paralleled lower myocardial inflammation and reduced fibrosis. These novel data showing the benefits of MCP in compliance and ECM remodeling in IR reinforces previously published data showing the therapeutic potential of Gal-3 inhibition.

Predictive Value of Tissue Doppler Imaging For Left Ventricular Ejection Fraction And Infarct Size Versus Myocardial Perfusion Imaging After Primary Percautaneous Coronary Intervention For Acute Myocardial Infarction

Predictive Value of Tissue Doppler Imaging For Left Ventricular Ejection Fraction And Infarct Size Versus Myocardial Perfusion Imaging After Primary Percautaneous Coronary Intervention For Acute Myocardial Infarction

Assessment of Myocardial Viability in Ischemic Heart Disease by PET/MRI: Comparison of Left Ventricular Perfusion, Hibernation, and Scar Burden

Hybrid positron emission tomography-magnetic resonance (PET-MR) is a novel imaging technology that enables a comprehensive assessment of myocardial viability. The aim of this study was to intra-individually compare simultaneously acquired viability parameters from MRI and PET to determine complementary and redundant information. Thirty-nine patients with ischemic heart disease (IHD) underwent cardiac PET-MR for myocardial viability assessment. Cardiac magnetic resonance (CMR), including late gadolinium enhancement (LGE), and PET, including a dynamic dual-tracer acquisition of [13N]ammonia ([13N]NH3)/[18F]fluorodeoxyglucose ([18F]FDG), were performed simultaneously. Allocation, extent, and transmural degree of left ventricular (LV) scars were measured from LGE. Perfusion, viability, and hibernation were assessed by PET. A comparison of scar location revealed six more areas of infarction on MR than on PET. Mean LV scarring by CMR was 14% (range, 2% to 42%) and 14% (range, 1% to 46%) by PET (CMR vs. PET: p = 0.9). An intra-individual comparison of scarring showed a good inter-method correlation (r = 0.7), which was also evident in the subgroup with low ejection fraction (EF) (r = 0.6). Hibernation and transmural degree of scars showed a moderate to weak correlation (r = 0.4), which was even worse in the low EF group (r = 0.1). In patients with IHD, there was a good correlation between PET and CMR for the LV scar extent using hybrid cardiac PET-MR. The degree of transmural scarring by CMR showed no correlation to PET hibernation. Therefore, cardiac PET-MR might be a suitable tool for a comprehensive assessment of myocardial viability if used to predict response to cardiac reperfusion strategies.

Interactions between myocardial sympathetic denervation and left ventricular mechanical dyssynchrony: A CZT analysis

BackgroundA correlation between left ventricular (LV) dyssynchrony (LVD) and impaired myocardial sympathetic tone has been hypothesized. We sought to assess the interactions between regional LV sympathetic innervation, perfusion, and mechanical dyssynchrony. MethodsEighty-three patients underwent evaluation of LV perfusion and sympathetic innervation on 99mTc-tetrofosmin/123I-metaiodobenzylguanidine (123I-MIBG) imaging. The summed rest score and summed 123I-MIBG score (SS-MIBG) were computed. The extent of “innervation/perfusion” mismatch was defined as the number of denervated LV segments with relatively preserved perfusion. LVD was evaluated on phase analysis and the wall with latest mechanical activation identified. ResultsLVD was revealed in 36 (43%) patients. Patients with LVD had more abnormal values of SRS (21 ± 9 vs 10 ± 8, P < 0.001) and SS-MIBG (29 ± 9 vs 17 ± 11, P < 0.001) than those without LVD. The presence of LVD also clustered with a higher burden of “innervation/perfusion” mismatch (P = 0.019). On per-wall analysis, LV walls with delayed mechanical activation showed a higher burden of “innervation/perfusion” mismatch (2.3 ± 1.4 segments) than normally contracting walls (1.3 ± 1.2 segments; P < 0.001). On multivariate analysis, the extent of “innervation/perfusion” mismatch was the only predictor of delayed mechanical activation (P = 0.029). ConclusionsPatients with LVD show an elevated burden of “innervation/perfusion” mismatch that is concentrated at the level of the most dyssynchronous walls.

PERSISTENT ALCAPA PHYSIOLOGY AFTER ALCAPA REPAIR

Left ventricular (LV) perfusion in anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) relies on right coronary artery (RCA) collaterals prior to repair. The Takeuchi repair for ALCAPA entails the creation of an aortopulmonary baffle (APB) which incorporates the left

Thyroid stimulating hormone suppression time on cardiac function of patients with differentiated thyroid carcinoma

BackgroundThis study was to investigate the influence of thyroid stimulating hormone (TSH) suppression time on the cardiac function of differentiated thyroid carcinoma (DTC) patients.Methods105 DTC patients were divided into strict TSH suppression group (model group, TSH ≤ 0.1 mU/L) and general TSH suppression group (control group, TSH > 0.1 mU/L). According to the suppression time, these two groups were respectively divided into three groups: group within half a year, group between half a year and a year and group more than a year. Gated myocardial perfusion imaging was applied to observe differences of left ventricle (LV) myocardial perfusion, LV diastolic and systolic function and LV systolic synchrony in every group.ResultsThe left ventricular diastolic function, systolic synchrony and myocardial perfusion level of model group decreased with prolonged suppression time. The values of left ventricular EF, PFR and BPM in patients less than half a year were higher than those in 6 months to 1 year for control group.ConclusionThyroid stimulating hormone suppression can influence the cardiac function of patients and with the prolongation of suppression time, regardless of the level of TSH suppression, the possibility of cardiac function depression in patients will increase. TSH may lower the risk of cardiovascular disease in high-risk patients than those in TSH patients with moderate or low risk. The drugs improving cardiac function should be used cooperatively in different suppression period to decrease the occurrence rate of cardiac adverse reactions.

Left ventricular subclinical myocardial dysfunction in uncomplicated type 2 diabetes mellitus is associated with impaired myocardial perfusion: a contrast-enhanced cardiovascular magnetic resonance study

BackgroundEarly detection of subclinical myocardial dysfunction in patients with diabetes mellitus (DM) is essential for recommending therapeutic interventions that can prevent or reverse heart failure, thereby improving the prognosis in such patients. This study aims to quantitatively evaluate left ventricular (LV) myocardial deformation and perfusion using cardiovascular magnetic resonance (CMR) imaging in patients with type 2 diabetes mellitus (T2DM), and to investigate the association between LV subclinical myocardial dysfunction and coronary microvascular perfusion.MethodsWe recruited 71 T2DM patients and 30 healthy individuals as controls who underwent CMR examination. The T2DM patients were subdivided into two groups, namely the newly diagnosed DM group (n = 31, patients with diabetes for ≤ 5 years) and longer-term DM group (n = 40, patients with diabetes > 5 years). LV deformation parameters, including global peak strain (PS), peak systolic strain rate, and peak diastolic strain rate (PSDR), and myocardial perfusion parameters such as upslope, time to maximum signal intensity (TTM), and max signal intensity (Max SI, were measured and compared among the three groups. Pearson’s correlation was used to evaluate the correlation between LV deformation and perfusion parameters.ResultsPooled data from T2DM patients showed a decrease in global longitudinal, circumferential, and radial PDSR compared to healthy individuals, apart from lower upslope. In addition, increased TTM and reduced Max SI were found in the longer-term diabetics compared to the normal subjects (p < 0.017 for all). Multivariable linear regression analysis showed that T2DM was independently associated with statistically significant CMR parameters, except for TTM (β = 0.137, p = 0.195). Further, longitudinal PDSR was significantly associated with upslope (r = − 0.346, p = 0.003) and TTM (r = 0.515, p < 0.001).ConclusionsOur results imply that a contrast-enhanced 3.0T CMR can detect subclinical myocardial dysfunction and impaired myocardial microvascular perfusion in the early stages of T2DM, and that the myocardial dysfunction is associated with impaired coronary microvascular perfusion.

Relationships between left ventricular sympathetic innervation and diastolic dysfunction: the role of myocardial innervation/perfusion mismatch

BackgroundA possible relationship between cardiac sympathetic denervation and left ventricular (LV) diastolic dysfunction has been suggested. However, an evaluation of the interactions between myocardial adrenergic tone and LV perfusion and diastolic function is lacking. Methods and resultsSeventy-two patients underwent 99mTc-tetrofosmin/123I-metaiodobenzylguanidine (123I-MIBG) cardiac Cadmium-Zinc-Telluride (CZT) imaging. The summed rest score (SRS) and summed 123I-MIBG score (SS-MIBG) were computed as measures of regional perfusion and innervation heterogeneities. LV segments showing an impaired innervation, despite a relatively preserved perfusion (99mTc-tetrofosmin-123I-MIBG tracers’ uptake ≥25%), were individuated (innervation/perfusion mismatch). The peak filling rate (PFR) was computed as a measure of LV diastolic function. Nineteen of the 72 (26%) patients presented a normal LV diastolic function, while 29 (40%) and 24 (34%) had a mild and overt diastolic dysfunction. Subjects with diastolic dysfunction showed more abnormal SRS and SS-MIBG values (P < 0.001). In the global population, 502/1224 (41%) LV segments showed an innervation/perfusion mismatch. A modest correlation between the extent of cardiac innervation/perfusion mismatch and PFR values was evident (R = −0.27, P = 0.029). On multivariate analysis, the extent of regional innervation/perfusion mismatch remained an independent predictor of overt LV diastolic abnormalities (P = 0.017). ConclusionsThe burden of LV regions showing an innervation/perfusion mismatch associates with the occurrence of overt diastolic dysfunction.

Cardiac shock wave therapy improves myocardial perfusion and preserves left ventricular mechanics in patients with refractory angina: A study with speckle tracking echocardiography.

Cardiac shockwave therapy (CSWT) is a new potential option for the treatment of patients with chronic coronary disease and refractory angina (RA). We aimed to study the effects of CSWT on left ventricular myocardial perfusion and mechanics in patients with RA. We prospectively studied 19 patients who underwent CSWT. Left ventricular mechanics were evaluated by speckle tracking echocardiography (STE), and myocardial perfusion by single-photon emission computed tomography, using stress/rest-Technetium-99m Sestamibi, for determination of summed stress score (SSS). Canadian Cardiac Society (CCS), New York Heart Association (NYHA), and quality of life by Seattle Angina Questionnaire (SAQ) were assessed at baseline and 6months after therapy. CSWT therapy was applied without major side effects. At baseline, 18 patients (94.7%) had CCS class III or IV, and after CSWT there was reduction to 3 (15.8%), P=.0001, associated with improvement in SAQ (38.5%; P<.001). Thirteen (68.4%) had class NYHA III or IV before treatment, with significant reduction to 7 (36.8%); P=.014. No change was observed in the global SSS from baseline to 6-month follow-up (15.33±8.60 vs 16.60±8.06; P=.157). However, there was a significant reduction in the average SSS of the treated ischemic segments (2.1±0.87 pre vs 1.6±1.19 post CSWT; P=.024). Global longitudinal strain by STE remained unaltered (-13.03±8.96 pre vs -15.88±3.43 6-month post CSWT; P=.256). CSWT is a safe procedure for the treatment of patients with RA that results in better quality of life, improvement in myocardial perfusion of the treated segments with preservation of left ventricular mechanics.

Left bundle branch block: Epidemiology, etiology, anatomic features, electrovectorcardiography, and classification proposal

In left bundle branch block (LBBB), the ventricles are activated in a sequential manner with alterations in left ventricular mechanics, perfusion, and workload resulting in cardiac remodeling. Underlying molecular, cellular, and interstitial changes manifest clinically as changes in size, mass, geometry, and function of the heart. Cardiac remodeling is associated with progressive ventricular dysfunction, arrhythmias, and impaired prognosis. Clinical and diagnostic notions about LBBB have evolved from a simple electrocardiographic alteration to a critically important finding affecting diagnostic and clinical management of many patients. Advances in cardiac magnetic resonance imaging have significantly improved the assessment of patients with LBBB and provided additional insights into pathophysiological mechanisms of left ventricular remodeling. In this review, we will discuss the epidemiology, etiologies, and electrovectorcardiographic features of LBBB and propose a classification of the conduction disturbance.