Variability and reproducibility of quantitative left ventricular angiography

Predictors of Left Ventricular Ejection Fraction Improvement After Primary Stenting in ST-Segment Elevation Myocardial Infarction (from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction Trial)

The predictors of improvement in left ventricular ejection fraction (LVEF) after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) are poorly understood. We sought to determine the prevalence and clinical and angiographic predictors of LVEF improvement after primary PCI in STEMI. In the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction trial, 3,602 patients presenting with STEMI were randomized to heparin + a glycoprotein IIb/IIIa inhibitor versus bivalirudin. Routine 13-month angiographic follow-up was performed in a prespecified substudy of 656 stented patients. The median [25%, 75%] change in LVEF from baseline to 13 months was +2.4% [-5.9%, 11.8%]; LVEF increased or remained unchanged in 379 patients (57.8%; median Δ +9.8% [4.3%, 16.4%]) and fell in 277 patients (42.2%; median Δ -7.0% [-11.8%, -3.6%]). Independent predictors of LVEF improvement were female gender (p = 0.002), lower baseline LVEF (p <0.0001), Thrombolysis in Myocardial Infarction 3 flow after PCI (p = 0.03), shorter lesion length (p = 0.04), and lower post-PCI peak MB isoenzyme of creatine kinase (p <0.0001). In conclusion, in the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction trial, although LVEF improved during follow-up after primary PCI in more than half of patients, left ventricular function worsened over time in a substantial proportion, the occurrence of which may be predicted by clinical, angiographic, and laboratory variables.

A system for postoperative visualization and analysis of left ventricular pressure-volume loops

A patient monitoring system for continuous real-time monitoring of left ventricular (LV) function in the postoperative setting was developed. Common hemodynamic parameters and LV functional indices are all calculated from left ventricular pressure-volume loops (PV-loops). Visualization of the PV-loops, along with the hemodynamic parameter derived from them, provides valuable insight into ventricular function and patient recovery. The pressure component is obtained via a pressure sensing catheter placed during surgery. Volume is measured via non-imaging radionuclide techniques using a modified Capintec-VEST. Following surgery and transfer to the recovery unit, the patient's blood is labeled with Tc-99m. A portable gamma camera is used to measure baseline ejection fraction (EF) and to aid in placing the VEST. The specific radioactivity of the blood is calibrated using the baseline EF and thermodilution cardiac output. To confirm the volume measurement accuracy of this technique six patients undergoing bilateral heart catheterization were studied. Single-plane cineventriculographic LV volumes were compared to those calculated from the VEST's time activity curve.

Doppler-derived aortic maximal acceleration. A reliable index of left ventricular systolic function

We compared maximal acceleration of aortic blood flow (aortic Amax), calculated from maximal aortic velocity obtained with a conventional echo-Doppler machine with the invasive inotropic index left ventricular end-systolic pressure/left ventricular end-systolic volume (LVESP/LVESV) ratio and left ventricular ejection fraction (LVEF). Continuous wave (CW) and pulsed wave (PW) Doppler aortic blood flows were recorded from the apical view in 16 patients (age, 62.3 +/- 6.4 years) within 24 h of left-sided catheterization. The theoretical exponential relationship between LVEF and LVESP/LVESV was confirmed in our study population (r = 0.92; p < 0.0001). The relationship between aortic Amax determined either by CW or PW and LVESP/LVESV was linear (r = 0.92 and 0.93, respectively, p < 0.001), whereas the relationship between aortic Amax and angiographic LVEF was exponential (PW: r = 84; CW: r = 0.85; both p < 0.001). We conclude that (1) aortic Amax, derived from maximal velocity obtained with a conventional machine, can be used as an index of left ventricular systolic function, and (2) PW as well as CW Doppler signals can be used for this calculation.

Analysis of left ventricular function from gated first-pass and multiple gated equilibrium acquisitions

99mTechnetium-sestamibi is a new myocardial perfusion imaging agent that offers significant physical advantages over 201thallium for myocardial perfusion imaging. One of these advantages is that it can be used in the assessment of ventricular function by means of first-pass radionuclide angiography (FPRNA), acquired during the injection of the tracer. In this study we compared gated list mode first-pass acquisition with 99mTc-sestamibi (FP-MIBI) to multiple gated equilibrium radionuclide ventriculography (MUGA) with 99mTc-labelled red blood cells for the determination of global left ventricular ejection fraction (LVEF). The study population consisted of 20 patients (mean age 54 years) who were submitted to stress-rest perfusion imaging. Resting FPRNA was performed using 99mTc-sestamibi and the reference data were acquired within a week with the MUGA technique. A linear correlation between FP LVEF and MUGA LVEF gave an r = 0.974 (p < 0.01). Diastolic and systolic timing and velocity parameters had lower correlations between these two methods. We conclude that global LVEF can be precisely measured with 99mTc-sestamibi when compared to usually employed MUGA technique with 99mTc-labelled red blood cells.

Catheter optimization during contrast ventriculography: a prospective randomized trial

Although newer contrast mediums have improved hemodynamic stability during left ventriculography, the image quality and hence the diagnostic yield of the procedure is largely determined by the choice of catheter and injection technique. In this study 125 patients were prospectively assigned at random to undergo ventriculography using either of two pigtail catheters, one with a straight shaft throughout its length (straight) and one with a 145-degree bend placed 6.5 cm from the distal end (angled). Injectate composition, flow rate, and volume were held constant for all injections, and baseline clinical and catheterization variables were found to be similar in each group. The angled catheter exhibited a statistically superior ease of insertion (p = 0.038) and took less time to position (p = 0.012), saving a mean of 23 seconds of fluoroscopy time per procedure. It was also associated with superior contour edge definition (p = 0.037) and a trend toward more uniform distribution of contrast medium (p = 0.089). Compared with the straight catheter, the angled catheter was less frequently accompanied by artifactual mitral regurgitation (p = 0.038) but was equally likely to provoke ventricular arrhythmias during injection. These observed differences may be explained in part by the tendency for angled catheters to more frequently localize in the central as opposed to the inferoposterior region of the left ventricular cavity (mean distance from center = 0.53 vs 1.10 cm, respectively; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)