Volume 1 Issue 1

Research Article: Changes in Carotid Radial Pulse Wave Velocity Induced by Hyperemia and Passive Leg Rising

Manasi Bapat, Atif Afzal, David Chabbott, Daniel Fung, Muhammad Fahad Mughal, Hue Van Le, Haroon Kamran, Louis Salciccioli, Jason Lazar*

Carotid to Radial Pulse Wave Velocity (CR-PWV) normally decreases the following hyperemia and has been proposed to assess arterial vasodilator reserve. Passive Leg Raising (PLR) also elicits brachial artery dilation. Using applanation tonometry, we assessed changes (Δ) in CR-PWV induced by PLR in 54 subjects with/without cardiovascular disease/risk factors (age 44 ± 18 years). CR-PWV was assessed before and 1 minute after each hyperemia (release of brachial artery occlusion) and PLR to 60 degrees. Both provocations significantly decreased CR-PWV (8.9 ± 1.6 to 7.7 ± 1.5 m/s, p < 0.001) and (8.8 ± 1.5 to 8.0 ± 1.7 m/s, p < 0.001) with greater decline for hyperemia than PLR (-12.9% vs. -8.8%, p = 0.037). %ΔPWV induced by both techniques were significantly correlated on univariate (r = 0.42, p = 0.002) and multivariate analyses. In conclusion, PLR decreases PWV. %?PWV induced by PLR is correlated with but less in magnitude than %?PWV induced by hyperemia. Clinical factors associated with PLR-CR-PWV responses and the prognostic value merit further study.

Cite this Article: Bapat M, Afzal A, Chabbott D, Fung D, Mughal MF, et al. Changes in Carotid Radial Pulse Wave Velocity Induced by Hyperemia and Passive Leg Rising. SRL Cardiol. 2017;1(1): 043-047.

Published: 20 February 2017

Review Article: Magnetic Resonance Imaging in Coronary Interventions and Myocardial Microinfarction

Maythem Saeed* and Mark W. Wilson

Coronary Artery Bypass Grafting (CABG) and Percutaneous Coronary Intervention (PCI) were introduced in 1968 and 1977, respectively. Currently these procedures are used for the treatment of ischemic heart disease. The procedures are safe and can achieve effective relief of coronary arterial obstruction in 90% to 95% of patients. Other investigators also found these procedures often generate macro- and micro-emboli resulting in additional damage. A recent SYNTAX trial showed that the rates of myocardial infarction and death at 1 year were similar between patients who underwent CABG and those who underwent PCI. Unlike Doppler sonography, Magnetic Resonance Imaging (MRI) has not been used for counting circulating coronary micro-emboli during coronary interventions. On the other hand, MRI provides valuable information on coronary artery anatomy, cardiac function, myocardial perfusion and viability. It also has the potential to reliably assess the beneficial effects of new therapies. However, the detection of myocardial microinfarct micro-emboli in patients is still challenging, because of the large variability in the volumes/sizes of dislodged micro-emboli and microinfarct sizes after coronary interventions. The spatial resolution of MR scanners and relaxivity of contrast media play important role in visualizing microinfarct. Recent clinical and preclinical techniques were able to count coronary micro-emboli and demonstrate myocardial microinfarct. These studies shed light on the complex relationship between coronary interventions and myocardial microinfarct. Preclinical studies, however, indicated that delayed contrast enhanced MRI underestimates microinfarct size compared with histopathology. Recent studies revealed that micro-emboli were cleared from the vasculature compartment by either hemodynamic pressure or angiography. The ability to detect, characterize and size intraoperative occurring coronary emboli, using non-invasive imaging techniques, may have a great potential for patient's safety. At this time, there are no known drugs/device that have demonstrated conclusively myocardial protection.

Cite this Article: Saeed M, Wilson MW. Magnetic Resonance Imaging in Coronary Interventions and Myocardial Microinfarction. SRL Cardiol. 2017;1(1): 031-042.

Published: 13 February 2017

Research Article: A Novel Mechanism to Reduce Myocardial Remodeling: The Nitric Oxide Synthase Inhibitor L-NAME Shields the Remote Myocardium from Apoptosis and Fibrosis after Myocardial Infarction in-vivo

Felix M. Heidrich*, Anna Ritzkat, David M. Poitz, Annette Ebner, Melissa M. Cremers, Tobias F. Ruf, Silvio Quick, Christian Pfluecke, Ruth H. Strasser and Stephan Wiedemann

Rationale: Following Myocardial Infarction (MI), apoptosis contributes to the processes of myocardial remodeling. Nitrosative stress is a well-known inductor of myocardial apoptosis. Activation and differential phosphorylation of Endothelial Nitric Oxide Synthase (eNOS) may increase its uncoupling potential, resulting in an excess of peroxynitrite formation. However, the pathophysiologic impact of eNOS signaling in the remote myocardium after MI until now is unexplored.
Objective: The goal of the present study was to assess the impact of eNOS signaling on Heart Failure (HF) development, the induction and execution of apoptosis, and fibrotic remodeling in the remote, non-ischemic myocardium in vivo.
Methods and Results: NOS inhibition was achieved in a rat MI animal model in vivo using the specific NOS-inhibitor N?-Nitro-L-arginine methyl ester (L-NAME). L-NAME treatment for 14 days after MI significantly ameliorated para-clinical and clinical HF indices (N-terminal pro-atrial natriuretic peptide, heart-to-body weight ratio, lung water content). Moreover, L-NAME treatment prevented effector caspase 3 activation and led to significantly less apoptosis execution and fibrotic remodeling in the remote myocardium. Notably, L-NAME treatment prevented harmful eNOS-phosphorylation at threonine (495), resulting in a preserved serine (1177)/threonine (495) eNOS phosphorylation ratio.
Conclusion: These data demonstrate that apoptosis execution and fibrotic remodeling after MI in the remote, non-ischemic myocardium are the consequence of increased eNOS-phosphorylation at threonine (495).Treatment with L-NAME not only restored eNOS serine (1177)/threonine (495) phosphorylation ratio but also reduced apoptosis execution and fibrotic remodeling. Therefore, modulating differential eNOS phosphorylation might become an important pharmacological target for the development of novel tailored therapies to prevent myocardial remodeling and the development of HF.
Keywords: Experimental myocardial infarction; Myocardial remodeling; Apoptosis; Endothelial nitric oxide synthase; Nitric oxide

Cite this Article: Heidrich FM, Ritzkat A, Poitz DM, Ebner A, Cremers MM, et al. A Novel Mechanism to Reduce Myocardial Remodeling: The Nitric Oxide Synthase Inhibitor L-NAME Shields the Remote Myocardium from Apoptosis and Fibrosis after Myocardial Infarction in-vivo. SRL Cardiol. 2017;1(1): 020-030.

Published: 13 February 2017

Research Article: Relationship between Serum Lactate Levels and Postoperative Outcomes in Patients undergoing On-Pump Coronary Bypass Surgery

Haluk Mevre Ozgoz, Ahmet Yuksel*, Mustafa Tok, Murat Bicer, Isik Senkaya Signak

Objective: To evaluate the relationship between serum lactate levels and postoperative outcomes in patients who underwent on-pump Coronary Artery Bypass Grafting (CABG).
Methods: A prospective analysis was performed on 40 adult patients who underwent isolated first-time on-pump CABG between December 2014 and March 2015. Patients were divided into two groups according to their postoperative serum lactate levels as patients with higher levels (=3 mmol/ L) and lower levels (<3 mmol/ L). Patients' demographics, risk factors, intraoperative and postoperative data were recorded. Serum lactate levels and postoperative mortality and morbidity rates in each group were compared and relationship between serum lactate levels and postoperative outcomes was evaluated.
Results: Patients with normal serum lactate levels accounted for 82.5% (n = 33) of study population whereas patients with high blood lactate levels comprised 17.5% (n = 7). There were no statistically significant difference between two groups according to the preoperative patients' demographics. According to the intraoperative data; aortic cross clamp, cardiopulmonary bypass and operation time was significantly higher in high lactate group than normal lactate group. In high lactate group, incidence of decreasing in mean arterial pressure under 60 mmHg was also significantly higher (100%) when compared to normal lactate group (45.5%). Postoperative data showed that hemodynamic instability occurrence and inotrope administration rates were significantly higher in high lactate group. Postoperative complications such as neurological complications, pneumonia and severe cardiac arrhythmias were observed more frequently in high lactate group.
Conclusion: Our study demonstrated that the high serum lactate levels were associated with the worse postoperative outcomes following on-pump CABG. Keywords: Lactate; Coronary Artery Bypass Grafting; Morbidity; Mortality

Cite this Article: Ozgoz HM, Yuksel A, Tok M, Bicer M, Signak IS. Relationship between Serum Lactate Levels and Postoperative Outcomes in Patients undergoing On-Pump Coronary Bypass Surgery. SRL Cardiol. 2017;1(1): 015-019.

Published: 03 February 2017

Research Article: Usefulness of MRI to Detect Pulmonary Hypertension in A Population Pre-Selected by Echocardiography

Clement Venner, Freddy Odille, Damien Voilliot, Ari Chaouat, Francois Chabot, Jacques Felblinger, Laurent Bonnemains*

Purpose: To evaluate the diagnostic power of cardiac MRI within an all-comers population of patients suspected of pulmonary hypertension after an echocardiography.
Methods: Fifty-six consecutive patients,suspected of pulmonary hypertension after an echocardiography, were assessed with right heart catheterization and cardiac MRI (including a high temporal resolution pulmonary flow curve). We extracted from the MR data the main parameters proposed by all precedent studies available in the literature. We looked for multivariate linear relations between those parameters and the mean pulmonary arterial pressure (mPAP), and eventually assessed with a logit regression the ability of those parameters to diagnosepulmonary hypertension in our population.
Results: The multivariate model retained only two parameters: the right ventricle ejection fraction and the pulmonary trunk minimum area. The prediction of mPAP (r2=0.5) yieldedlimits of agreement of 15mmHg. However the prediction of pulmonary hypertension within the population was feasible and the method yielded a specificity of 80% for a sensitivity of 100%.
Conclusion: The performance of MRI to assess mPAPis too low to be used as a surrogate to right heart catheterization but MRI could be used as second line examination after echocardiography to avoid right heart catheterization for normal patients.
Keywords: MRI; Pulmonary hypertension; Diagnostic power

Cite this Article: Venner C, Odille F, Voilliot D, Chaouat A, Chabot F, et al. Usefulness of MRI to Detect Pulmonary Hypertension in A Population Pre-Selected by Echocardiography. SRL Cardiol. 2017;1(1): 008-014.

Published: 05 January 2017

Research Article: Acute Procedural Results and Mid-Term Outcome of Electroanatomical Guided Pulmonary Vein Isolation: A Single Center Observational Study Comparing A Real-Time Contact Force Sensing Versus Standard Tip Irrigated Ablation Catheter

Mauro Toniolo*, Daniele Muser, Luca Rebellato, Elisabetta Daleffe and Alessandro Proclemer

The additional benefit of real time Contact Force (CF) measurement during Pulmonary Vein Isolation (PVI) to improve procedural parameters and clinical outcome is unclear. We prospectively assessed the impact of real time CF measurement on acute procedural parameters, procedural related complications and mid-term outcome.
One hundred consecutive patients (73 males) with paroxysmal (78%) or persistent (22%) Atrial Fibrillation (AF) who underwent PVI with CARTO® 3 Electro-Anatomical Mapping (EAM) system (Biosense Webster Inc.) were consecutively assigned to either Radio Frequency (RF) ablation using the 3.5mm open-irrigated-tip Navistar®Thermocool® catheter (50 patients, standard group) or the SmartTouchTM catheter with CF measurement capabilities (50 patients, CF group). PVI endpoint was set as validation of entry and exit block. Significant reduction in fluoroscopy time (57 ± 16min vs. 29 ± 16min) and a trend in reduction of procedural related complications (10% vs. 2%) was reported in CF group patients. No differences in mid-term risk of AF recurrence were observed between the two groups (8% in the CF group vs. 10% in the standard group at 12 months respectively. Log Rank test p=0.376). However, in CF group patients with higher (>13.5g) mean time-weighed CF resulted in a lower risk of 12 month follow-up AF recurrence (18% vs. 0%; p=0.041). In conclusion, our study confirm the procedural and technical improvement related to real time CF monitoring during PVI and show an halving of the fluoroscopy time in a large cohort of patients.

Cite this Article: Toniolo M, Muser D, Rebellato L, Daleffe E, Proclemer A. Acute Procedural Results and Mid-Term Outcome of Electroanatomical Guided Pulmonary Vein Isolation: A Single Center Observational Study Comparing A Real-Time Contact Force Sensing Versus Standard Tip Irrigated Ablation Catheter. SRL Cardiol. 2017;1(1): 001-007.

Published: 03 January 2017

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