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Find video protocols related to scientific articles indexed in Pubmed.
Intra-aortic balloon counterpulsation reduces mortality in large anterior myocardial infarction complicated by persistent ischaemia: a CRISP-AMI substudy.
EuroIntervention
PUBLISHED: 09-26-2014
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Aims: This substudy investigated IABP support in large STEMI complicated by persistent ischaemia within the original CRISP-AMI trial. Methods and results: Patients were included if the ECG at admission showed summed ST deviation (?ST-D) ?15 mm and the ECG post PCI showed poor ST resolution (<50%). Endpoints evaluated were all-cause mortality at six months and the composite endpoint of death, cardiogenic shock or new or worsening heart failure at six months. One hundred and forty-nine patients had ?ST-D ?15 mm (mean ?ST-D 24±8 mm). Of these patients, 36 (24%) showed poor ST resolution (15 patients in the IABP group; 21 patients in the control group). Mean age was 55±11 years, 89% were male. Mean systolic and diastolic blood pressures were 135±31 mmHg and 83±22 mmHg, respectively. The left anterior descending coronary artery was the infarct-related artery in all cases, primary PCI was successful in 94%. At six months, zero patients in the IABP group died versus five patients in the control group (0% versus 24%; p=0.046). There was a trend towards statistical significance in the composite endpoint (one patient [7%] versus seven patients [33%]; p=0.06). Conclusions: In this substudy, use of IABP was associated with decreased six-month mortality in large STEMI complicated by persistent ischaemia after PCI.
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Single bolus intravenous regadenoson injection versus central venous infusion of adenosine for maximum coronary hyperaemia in fractional flow reserve measurement.
EuroIntervention
PUBLISHED: 08-20-2014
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Aims: The aim of this study was to compare the hyperaemic effect of a single bolus regadenoson injection to a central venous adenosine infusion for inducing hyperaemia in the measurement of fractional flow reserve (FFR). Methods and results: One hundred patients scheduled for FFR measurement were enrolled. FFR was first measured by IV adenosine (140 µg/kg/min), thereafter by IV bolus regadenoson injection (400 µg), followed by another measurement by IV adenosine and bolus injection of regadenoson. The regadenoson injections were randomised to central or peripheral intravenous. Hyperaemic response and duration of steady state maximum hyperaemia were studied, central versus peripheral venous regadenoson injections were compared, and safety and reproducibility of repeated injections were investigated. Mean age was 66±8 years, 75% of the patients were male. The target stenosis was located in the LM, LAD, LCX, and RCA in 7%, 54%, 20% and 19%, respectively. There was no difference in FFR measured by adenosine or by regadenoson (?FFR=0.00±0.01, r=0.994, p<0.001). Duration of maximum hyperaemia after regadenoson was variable (10-600 s). No serious side effects of either drug were observed. Conclusions: Maximum coronary hyperaemia can be achieved easily, rapidly, and safely by one single intravenous bolus of regadenoson administered either centrally or peripherally. Repeated regadenoson injections are safe. The hyperaemic plateau is variable. Clinical Trial Registration: http://clinicaltrials.gov/ct2/show/study/NCT01809743?term=NCT01809743&rank=1 (ClinicalTrials.gov Identifier: NCT01809743).
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Long-term comparison of sirolimus-eluting and bare-metal stents in ST-segment elevation myocardial infarction.
Coron. Artery Dis.
PUBLISHED: 04-17-2014
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We aimed to investigate, in patients with ST-segment elevation myocardial infarction (STEMI), whether the previously reported clinical benefits of sirolimus-eluting stent(s) (SES) in terms of reducing a major adverse cardiac and cerebrovascular event (MACCE) compared with bare-metal stent(s) (BMS) were maintained over a 5-year time period.
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Volume quantification by contrast-enhanced ultrasound: an in-vitro comparison with true volumes and thermodilution.
Cardiovasc Ultrasound
PUBLISHED: 07-11-2013
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Contrast-enhanced ultrasound (CEUS) has recently been proposed as a minimally- invasive, alternative method for blood volume measurement. This study aims at comparing the accuracy of CEUS and the classical thermodilution techniques for volume assessment in an in-vitro set-up.
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Multicenter Core Laboratory Comparison of the Instantaneous Wave-Free Ratio and Resting Pd/Pa with Fractional Flow Reserve: The RESOLVE Study.
J. Am. Coll. Cardiol.
PUBLISHED: 07-08-2013
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We sought to examine the diagnostic accuracy between the instantaneous wave-free ratio (iFR) and resting Pd/Pa with respect to hyperemic fractional flow reserve (FFR) in a core laboratory-based multicenter collaborative study.
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Modeling the interaction between the intra-aortic balloon pump and the cardiovascular system: the effect of timing.
ASAIO J.
PUBLISHED: 06-07-2013
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Because of the large number of interaction factors involved, the effects of the intra-aortic balloon pump (IABP) have not been investigated deeply. To enhance its clinical efficiency and to better define indications for use, advanced models are required to test the interaction between the IABP and the cardiovascular system. A patient with mild blood pressure depression and a lowered cardiac output is modeled in a lumped parameter computational model, developed with physiologically representative elements for relevant components of circulation and device. IABP support is applied, and the moments of balloon inflation and deflation are varied around their conventional timing modes. For validation purposes, timing is adapted within acceptable ranges in ten patients undergoing IABP therapy for typical clinical indications. In both model and patients, the IABP induces a diastolic blood pressure augmentation as well as a systolic reduction in afterload. The support capabilities of the IABP benefit the most when the balloon is deflated simultaneously with ventricular contraction, whereas inflation before onset of diastole unconditionally interferes with ejection. The physiologic response makes the model an excellent tool for testing the interaction between the IABP and the cardiovascular system, and how alterations of specific IABP parameters (i.e., timing) affect this coupling.
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Autoregulation of coronary blood flow in the isolated beating pig heart.
Artif Organs
PUBLISHED: 03-13-2013
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The isolated beating pig heart model is an accessible platform to investigate the coronary circulation in its truly morphological and physiological state, whereas its use is beneficial from a time, cost, and ethical perspective. However, whether the coronary autoregulation is still intact is not known. Here, we study the autoregulation of coronary blood flow in the working isolated pig heart in response to brief occlusions of the coronary artery, to step-wise changes in left ventricular loading conditions and contractile states, and to pharmacologic vasodilating stimuli. Six slaughterhouse pig hearts (473?±?40?g) were isolated, prepared, and connected to an external circulatory system. Through coronary reperfusion and controlled cardiac loading, physiological cardiac performance was achieved. After release of a coronary occlusion, coronary blood flow rose rapidly to an equal (maximum) level as the flow during control beats, independent of the duration of occlusion. Moreover, a linear relation was found between coronary blood flow and coronary driving pressure for a wide variation of preload, afterload, and contractility. In addition, intracoronary administration of papaverine did not yield a transient increase in blood flow indicating the presence of maximum coronary hyperemia. Together, this indicates that the coronary circulation in the isolated beating pig heart is in a permanent state of maximum hyperemia. This makes the model excellently suitable for testing and validating cardiovascular devices (i.e., heart valves, stent grafts, and ventricular assist devices) under well-controlled circumstances, whereas it decreases the necessity of sacrificing large mammalians for performing classical animal experiments.
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Evaluation of the lower limb vasculature before free fibula flap transfer. A prospective blinded comparison between magnetic resonance angiography and digital subtraction angiography.
Microsurgery
PUBLISHED: 02-22-2013
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Introduction The aim of this study was to compare magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) in the preoperative assessment of crural arteries and their skin perforators prior to free fibular transfer. Patients and methods Fifteen consecutive patients, scheduled for free vascularized fibular flap transfer, were subjected to DSA as well as MRA of the crural arteries of both legs (n = 30). All DSA and MRA images were assessed randomly, blindly, and independently by two radiologists. Each of the assessors scored the degree of stenosis of various segments on a 5 point scale from 0 (occlusive) to 4 (no stenosis). The Cohens Kappa coefficient was used to assess the agreement between DSA and MRA scores. In addition, the number of cutaneous perforators were scored and the assessors were asked if they would advise against fibula harvest and transplantation based on the images. Results A Cohens Kappa of 0.64, indicating "substantial agreement of stenosis severity scores" was found between the two imaging techniques. The sensitivity of MRA to detect a stenosis compared with DSA was 79% (CI95%:60-91), and a specificity of 98% (CI95%: 97-99). In 53 out of 60 assessments, advice on suitability for transfer were equal between DSA and MRA. The median number of cutaneous perforators that perfuse the skin overlying the fibula per leg was one for DSA as well as MRA (P = 0.142).Conclusions A substantial agreement in the assessment of stenosis severity was found between DSA and MRA. The results suggest that MRA is a good alternative to DSA in the preoperative planning of free fibula flap transplantation. © 2013 Wiley Periodicals, Inc. Microsc. Res. Tech., 2013.
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Does the instantaneous wave-free ratio approximate the fractional flow reserve?
J. Am. Coll. Cardiol.
PUBLISHED: 02-06-2013
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This study sought to examine the clinical performance of and theoretical basis for the instantaneous wave-free ratio (iFR) approximation to the fractional flow reserve (FFR).
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VERIFY (VERification of Instantaneous Wave-Free Ratio and Fractional Flow Reserve for the Assessment of Coronary Artery Stenosis Severity in EverydaY Practice): a multicenter study in consecutive patients.
J. Am. Coll. Cardiol.
PUBLISHED: 02-06-2013
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This study sought to compare fractional flow reserve (FFR) with the instantaneous wave-free ratio (iFR) in patients with coronary artery disease and also to determine whether the iFR is independent of hyperemia.
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Towards patient-specific modeling of coronary hemodynamics in healthy and diseased state.
Comput Math Methods Med
PUBLISHED: 01-03-2013
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A model describing the primary relations between the cardiac muscle and coronary circulation might be useful for interpreting coronary hemodynamics in case multiple types of coronary circulatory disease are present. The main contribution of the present study is the coupling of a microstructure-based heart contraction model with a 1D wave propagation model. The 1D representation of the vessels enables patient-specific modeling of the arteries and/or can serve as boundary conditions for detailed 3D models, while the heart model enables the simulation of cardiac disease, with physiology-based parameter changes. Here, the different components of the model are explained and the ability of the model to describe coronary hemodynamics in health and disease is evaluated. Two disease types are modeled: coronary epicardial stenoses and left ventricular hypertrophy with an aortic valve stenosis. In all simulations (healthy and diseased), the dynamics of pressure and flow qualitatively agreed with observations described in literature. We conclude that the model adequately can predict coronary hemodynamics in both normal and diseased state based on patient-specific clinical data.
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Gender differences in long-term outcome after primary percutaneous intervention for ST-segment elevation myocardial infarction.
Catheter Cardiovasc Interv
PUBLISHED: 01-01-2013
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Previous studies on gender differences in outcome in patients with ST segment elevation myocardial infarction (STEMI) have been performed, but most of those are from before the current era of PCI technique and medical therapy and have a short duration of follow-up. The objective of our study is to assess the influence of gender on long-term outcome in patients with STEMI who underwent primary percutaneous intervention (PCI) between January 2006 and May 2008.
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In vitro comparison of support capabilities of intra-aortic balloon pump and Impella 2.5 left percutaneous.
Artif Organs
PUBLISHED: 08-07-2011
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The Impella 2.5 left percutaneous (LP), a relatively new transvalvular assist device, challenges the position of the intra-aortic balloon pump (IABP), which has a long record in supporting patients after myocardial infarction and cardiac surgery. However, while more costly and more demanding in management, the advantages of the Impella 2.5 LP are yet to be established. The aim of this study was to evaluate the benefits of the 40 cc IABP and the Impella 2.5 LP operating at 47,000 rpm in vitro, and compare their circulatory support capabilities in terms of cardiac output, coronary flow, cardiac stroke work, and arterial blood pressure. Clinical scenarios of cardiogenic preshock and cardiogenic shock (CS), with blood pressure depression, lowered cardiac output, and constant heart rate of 80 bpm, were modeled in a model-controlled mock circulation, featuring a systemic, pulmonary, and coronary vascular bed. The ventricles, represented by servomotor-operated piston pumps, included the Frank-Starling mechanism. The systemic circulation was modeled with a flexible tube having close-to-human aortic dimensions and compliance properties. Proximally, it featured a branch mimicking the brachiocephalic arteries and a physiological correct coronary flow model. The rest of the systemic and pulmonary impedance was modeled by four-element Windkessel models. In this system, the enhancement of coronary flow and blood pressure was tested with both support systems under healthy and pathological conditions. Hemodynamic differences between the IABP and the Impella 2.5 LP were small. In our laboratory model, both systems approximately yielded a 10% cardiac output increase and a 10% coronary flow increase. However, since the Impella 2.5 LP provided significantly better left ventricular unloading, the circulatory support capabilities were slightly in favor of the Impella 2.5 LP. On the other hand, pulsatility was enhanced with the IABP and lowered with the Impella 2.5 LP. The support capabilities of both the IABP and the Impella 2.5 LP strongly depended on the simulated hemodynamic conditions. Maximum hemodynamic benefits were achieved when mechanical circulatory support was applied on a simulated scenario of deep CS.
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Fractional flow reserve in unstable angina and non-ST-segment elevation myocardial infarction experience from the FAME (Fractional flow reserve versus Angiography for Multivessel Evaluation) study.
JACC Cardiovasc Interv
PUBLISHED: 04-22-2011
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The aim of this study was to study whether there is a difference in benefit of fractional flow reserve (FFR) guidance for percutaneous coronary intervention (PCI) in multivessel coronary disease in patients with unstable angina (UA) or non-ST-segment elevation myocardial infarction (NSTEMI), compared with stable angina (SA).
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Rapid detection of myocardial infarction with a sensitive troponin test.
Am. J. Clin. Pathol.
PUBLISHED: 02-26-2011
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Rapid identification and treatment of patients with a myocardial infarction (MI) is mandatory. We studied the diagnostic capacities of a sensitive troponin assay for detection of MI in emergency department patients within 2 hours after arrival. The study included 157 patients suspected of having non-ST-elevation acute coronary syndrome. Blood was drawn on arrival (T0) and 2 (T2), 6, and 12 hours later. At T2, a troponin concentration above the MI cutoff is 87% sensitive and 100% specific for MI detection (positive predictive value [PPV], 100%; negative predictive value [NPV], 96%). If a difference of more than 30% between the troponin measurements at T0 and T2 in the absence of an absolute troponin increase above the 99th percentile of a reference population is also considered indicative of MI, the sensitivity increases to 100% and specificity decreases to 87% (PPV, 70%; NPV, 100%). Sensitivity and specificity of creatine kinase-MB and myoglobin are lower than those of troponin. By using a sensitive troponin assay and simple algorithms, the diagnosis of MI can be determined within 2 hours after arrival at the emergency department. Measurement of myoglobin and creatine kinase-MB has no added value.
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Angiographic versus functional severity of coronary artery stenoses in the FAME study fractional flow reserve versus angiography in multivessel evaluation.
J. Am. Coll. Cardiol.
PUBLISHED: 06-29-2010
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The purpose of this study was to investigate the relationship between angiographic and functional severity of coronary artery stenoses in the FAME (Fractional Flow Reserve Versus Angiography in Multivessel Evaluation) study.
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Continuous infusion thermodilution for assessment of coronary flow: theoretical background and in vitro validation.
Med Eng Phys
PUBLISHED: 01-23-2009
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Direct volumetric assessment of coronary flow during cardiac catheterization has not been available so far. In the current study continuous infusion thermodilution, a method based on continuous infusion of saline into a selective coronary artery is evaluated. Theoretically, volumetric flow can be calculated from the known infusion rate (Q(i)), the temperatures of the blood (T(b)), the saline (T(i)), and the mixture downstream to the infusion site (T). We aimed to validate and optimize the measurement method in an in vitro model of the coronary circulation. Full mixing of infusate and blood was found to be the main prerequisite for accurate determination of the coronary flow. To achieve full mixing the influence of catheter design, infusion rate, and location of temperature measurement were assessed. We found that continuous infusion thermodilution slightly overestimated coronary flow determined by directly measured reference flow by 7+/-8%, over the entire physiological flow range of 50-250 ml/min. These results were found using a specially designed infusion catheter (infusion mainly through distally located sideholes), a high enough infusion rate (25 ml/min), and measurement of the mixing temperature between 5 and 8 cm distal from the tip of the infusion catheter. Absolute coronary flow rate can be measured reliably by the continuous infusion method when full mixing is present, under the conditions mentioned above.
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Fractional flow reserve versus angiography for guiding percutaneous coronary intervention.
N. Engl. J. Med.
PUBLISHED: 01-16-2009
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In patients with multivessel coronary artery disease who are undergoing percutaneous coronary intervention (PCI), coronary angiography is the standard method for guiding the placement of the stent. It is unclear whether routine measurement of fractional flow reserve (FFR; the ratio of maximal blood flow in a stenotic artery to normal maximal flow), in addition to angiography, improves outcomes.
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Causes of nonlinearity of the oxygen uptake efficiency slope: a prospective study in patients with chronic heart failure.
Eur J Prev Cardiol
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BACKGROUND: The oxygen uptake efficiency slope (OUES) is an exercise parameter with strong prognostic value in the heart failure population. Yet, the optimal determination method of OUES remains unclear. The purpose of the present study was to investigate the influence of the ventilatory anaerobic threshold (VAT) and occurrence of a plateau in oxygen uptake (VO2) on determination of OUES from submaximal exercise data in patients with chronic heart failure (CHF). METHODS AND RESULTS: Ninety-eight CHF patients (New York Heart Association class II-III) were included. All patients performed a symptom-limited exercise test with gas exchange analysis on a cycle ergometer. VAT was determined by the V-slope method and OUES was derived via least-squares linear regression using 100% (OUES100), 90% (OUES90), and 75% (OUES75) of exercise duration, and, in addition, by using only the first 50% of data points preceding VAT (OUES½VAT), all data preceding VAT (OUESVAT), and only data following VAT (OUESpostVAT). Whereas OUESVAT (1720?±?430?ml/min/log(l/min)), OUES75 (1811?±?476?ml/min/log(l/min)), and OUESpostVAT (1742?±?564?ml/min/log(l/min)) were not significantly different from OUES100 (1767?±?542?ml/min/log(l/min)), OUES½VAT (1500?±?314?ml/min/log(l/min)) was significantly lower than all other values (p?
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The impact of downstream coronary stenoses on fractional flow reserve assessment of intermediate left main disease.
JACC Cardiovasc Interv
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The aim of this study was to assess the validity of measuring fractional flow reserve (FFR) of the left main (LM) coronary artery in the setting of concomitant left anterior descending (LAD) or left circumflex (LCX) stenoses.
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Variation of cardiac troponin I and T measured with sensitive assays in emergency department patients with noncardiac chest pain.
Clin. Chem.
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New-generation high-sensitivity assays for cardiac troponin have lower detection limits and less imprecision than earlier assays. Reference 99th-percentile cutoff values for these new assays are also lower, leading to higher frequencies of positive test results. When cardiac troponin concentrations are minimally increased, serial testing allows discrimination of myocardial infarction from other causes of increased cardiac troponin. We assessed various measures of short-term variation, including absolute concentration changes, reference change values (RCVs), and indices of individuality (II) for 2 cardiac troponin assays in emergency department (ED) patients.
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A combination of thermal methods to assess coronary pressure and flow dynamics with a pressure-sensing guide wire.
Med Eng Phys
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Measurement of coronary pressure and absolute flow dynamics have shown great potential in discerning different types of coronary circulatory disease. In the present study, the feasibility of assessing pressure and flow dynamics with a combination of two thermal methods, developed in combination with a pressure-sensor-tipped guide wire, was evaluated in an in vitro coronary model. A continuous infusion thermodilution method was employed to determine the average flow, whereas a thermal anemometric method was utilized to assess the pressure and flow dynamics, simultaneously. In the latter method, the electrical power supplied to an element, kept at constant temperature above ambient temperature, was used as a measure for the shear rate. It was found that, using a single calibration function, the method was able to assess coronary pressure and flow dynamics for different flow amplitudes, heart rates, and different pressure wires. However, due to the fact that the thermal anemometric method cannot detect local shear rate reversal, the method was unable to reliably measure flow dynamics close to zero. Nevertheless, the combined methodology was able to reliably assess diastolic hemodynamics. The diastolic peak flow and average diastolic resistance could be determined with a small relative error of (8 ± 7)% and (7 ± 5)%, respectively.
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Comparison of drug-eluting and bare-metal stents for primary percutaneous coronary intervention with or without abciximab in ST-segment elevation myocardial infarction: DEBATER: the Eindhoven reperfusion study.
JACC Cardiovasc Interv
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The goal of this study was to demonstrate superiority of sirolimus-eluting stents (SES) over bare-metal stents (BMS) and of abciximab over no abciximab in primary percutaneous coronary intervention (PCI).
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.