P2705Hybrid QFR-FFR decision making strategy for revascularization

Background Measurement of the fractional flow reserve (FFR) has become a standard practice for revascularization decision-making in evaluating the functional significance of angiographically intermediate epicardial coronary stenosis. The quantitative flow ratio (QFR) is a novel method for rapid computational estimation of FFR without pressure wire and vasodilator drugs. Purpose Nevertheless, the evidence was shown the clinical better outcome of coronary revascularization stratified by FFR, the adoption of FFR remains low. We hypothesized that combined QFR and FFR hybrid strategy could improve the physiological assessment without pressure wire and drugs. Methods and results We performed a post-hocanalysis of 549 vessels with angiographically intermediate stenosis in 549 patients who underwent measurement of FFR. The median FFR and QFR values were 0.81 (0.73–0.87) and 0.79 (0.74–0.87), respectively.The ischemic threshold was defined as 0.80 for both QFR and FFR measures. The diagnostic sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the QFR for predicting an FFR of ≤0.80 were 86.2%, 71.9%, 78.9%, 74.5%, and 84.5%, respectively. The area under the receiver operating characteristic curve using the cut-off threshold of ≤0.80 for the FFR was 0.85 (95% confidence interval [CI], 0.81–0.88) for the QFR.In total, 433 (78.9%) and 116 (21.1%) lesions showed concordant and discordant FFR and QFR functional classifications, respectively. A hybrid QFR-FFR strategy was developed, by allowing deferral when QFR values providing negative predictive value greater than 90% and treat others when QFR values greater than that showing 90% positive predictive value, with adenosine being given only to patients with QFR in between those values. For the FFR cut-off (0.8), an QFR of <0.73 could be used to confirm treatment (PPV of 90.7%), while an QFR value of >0.83 could be used to defer revascularization (NPV of 90.0%). When QFR values fall between 0.73 and 0.84, adenosine is given for hyperemic induction and the FFR cut-off of 0.8 is used to guide revascularization. This hybrid QFR-FFR approach has a 95% agreement with an FFR-only decision making, and 285 lesions (51.9%) would have obviated the need of a pressure wire and adenosine. Hybrid QFR-FFR strategy Conclusions A hybrid QFR-FFR strategy for coronary revascularization could reduce the need of a pressure wire and vasodilator drugs, which may increase the penetration of functional assessment of coronary lesions.

High-altitude pulmonary oedema

At high altitude, the reduction in arterial oxygenation frequently leads to symptoms of acute mountain sickness. While these symptoms generally resolve spontaneously, high-altitude pulmonary oedema can develop and represents a potentially lethal form of high-altitude disease. High-altitude pulmonary oedema is a non-cardiogenic oedema due to exaggerated pulmonary vasoconstriction and altered alveolar–capillary permeability. In addition to descending to lower altitude, it requires specific emergency cares such as oxygen administration, a hyperbaric bag, and vasodilator drugs.

Detection of vasodilator drugs through microwave spectroscopy of Au NP colorimetric probes using a microwave metallic photonic crystal-inspired resonant probe

A low-cost, time-effective and easy-to-use novel analytical technique incorporating microwave spectroscopy of unmodified gold nanoparticles for the detection of selected vasodilator drugs.

Vascular Reactivity during Cardiopulmonary Bypass in Patients at Punjab Institute of Cardiology & Shalamar Hospital Lahore, Pakistan

Background: The operative treatment of cardiac diseases remains associated with systemic inflammation and a suboptimal outcome in many patients. These inflammatory changes are manifested by systemic hypotension, myocardial failure, increased vascular permeability and consequent dysfunction of organs such as the lungs, gut and brain. In general terms, sympathetic innervations of the small arteries and arterioles allows vasoconstriction, thereby increasing resistance to blood flow, whereas innervations of the large arteries and veins decreases the volume in these vessels, resulting in the redistribution of blood volume. This study was conducted to determine the effect of vasodilator drugs on duration of vasodilatation in patients undergoing coronary artery bypass grafting (CABG) with Cardiopulmonary bypass (CPB).Methods: We evaluated prospectively the effect of vasodilator medications before CABG surgery on hemodynamic variables and use of vasoactive drugs. We studied 30 patients with good left ventricular function allocated randomly to continue vasodilator drugs before cardiac surgery. Arterial pressure, Cardiac output, systemic vascular resistance and use of vasoactive drugs were recorded during anaesthesia, perioperative and in the early postoperative period.Results: Patients who using vasodilator drugs before cardiac surgery had not significant relationship between vasodilator drugs and vessels reactivity (vasoconstriction & vasodilatation). However, these patients required more vasodilator drugs to control hypertension after CPB and in the early postoperative period.Conclusion: There was no difference in hypotension at the onset of CPB or in the use of vasodilator drugs before cardiac surgery. We conclude that vasodilator drugs before cardiac surgery did not have sufficient effect to be recommended routinely.

Vasodilators in critical illness

Vasodilators are commonly used in the intensive care unit (ICU) to control arterial blood pressure, unload the left or the right heart, control pulmonary artery pressure, and improve microcirculatory blood flow. Vasodilator refers to drugs acting directly on the smooth muscles of peripheral vessel walls and drugs are usually classified based on their mechanism (acting directly or indirectly) or site of action (arterial or venous vasodilator). Drugs that have a predominant effect on resistance vessels are arterial dilators and drugs that primarily affect venous capacitance vessels are venous dilators. Drugs that interfere with sympathetic nervous system, block renin-angiotensin system, phosphodiesterase inhibitors, and nitrates are some examples of drugs with indirect effect. Vasodilator drugs play a major therapeutic role in hypertensive emergencies, primary and secondary pulmonary hypertension, acute left heart, and circulatory shock. This review discusses the main types of vasodilators drugs commonly used in the ICU.

Liver Transplantation for Patients with Portopulmonary Hypertension: a Case Report and Review of the Literature

Portopulmonary hypertension is one of the complications for people with end stage chronic liver disease. This condition occurs to 5-8% of people, who need liver transplantation, and it causes a higher risk of perioperative complications or these patients are even banned from this procedure. Therefore, it is very important to diagnose this pathology in time using right heart catheterization and provocative volume and dobutamine samples for evaluation of the right ventricle function. Fortunately, adequate medical treatment with its most important part – vasodilator drugs - cures portopulmonary hypertension or lowers the perioperative risk caused by this condition. This case report presents a 50-year-old male hospitalized for liver transplantation. The patient has cirrhosis of the liver caused by hepatitis C, liver failure and portopulmonary hypertension. He has been taking vasodilator drugs for almost 8 months in order to prepare for a surgical treatment and when the operation’s day came, all tests needed including echocardiography shown that the transplantation could be performed. During the operation patient’s heart function was monitored with transesophageal echocardiography. Even though the mean pulmonary arterial pressure was marginal, the operation was successful and the patient could be extubated right after the procedure. Systolic pulmonary arterial pressure of the recipient dropped from 70 mmHg to 60.

Stress testing for myocardial perfusion scintigraphy

Coronary physiology and stress testing 76Practical requirements for stress testing 78Patient preparation for stress 80Exercise stress: general considerations 82Exercise stress: practical aspects 84Exercise stress: performing the test 86Vasodilator drugs: pharmacology 88Vasodilator drugs: practical considerations 92Vasodilator drugs: performing the stress test ...