An assessment of tissue harmonic versus fundamental imaging modes for echocardiographic measurements.

The study aimed to evaluate whether a significant difference exists between tissue harmonic imaging (THI) and fundamental imaging (FI) in routine quantitative echocardiographic assessment. We also examined the effects of THI on endocardial definition (ED). Fifty-eight unselected patients (29 men, 29 women; mean age 53 years) referred for transthoracic echocardiography were studied with use of both FI and THI modes. Two independent observers made M-mode measurements of the following: left atrium, aortic root, and left ventricular internal dimensions and wall thickness; they also measured left ventricular outflow tract diameter and left atrial area from 2-dimensional images. Endocardial definition was assessed with use of an arbitrary scoring system (0 = endocardium not visualized, 1 = endocardium visualized but suboptimally, 2 = endocardium well defined) and the American Society of Echocardiography 16-segment model. No significant difference existed between cardiac measurements derived from FI and THI. However, a highly significant improvement in ED occurred with THI (ED index 1.83 versus 1.70, P <.0001). This study suggests that no systematic differences exist in standard echocardiographic measurements between THI and FI, even in the setting of improved ED.

Echocardiologists' role in the deployment of the Amplatzer atrial septal occluder device in adults.

Use of the Amplatzer Septal Occluder device to close selected secundum atrial septal defects is ever-increasing. This article illustrates the central role of the echocardiologist before, during, and after percatheter closure with the Amplatzer Septal Occluder device. Figures, diagrams, and tables detail each stage of the evaluation, procedure, and postprocedural assessment.

Agreement between coronary flow velocity reserve and stress echocardiography in intermediate-severity coronary stenoses.

Visual and quantitative assessments of percent diameter stenosis on coronary angiography correlate poorly with functional testing, particularly in intermediate-severity (40%-70%) lesions, yet are frequently relied on to make decisions regarding revascularization. Coronary flow velocity reserve (CFVR) and relative CFVR (RCFVR) are promising methods for on-line functional assessment of lesion severity in the catheterization laboratory. We sought to determine the agreement between maximal, mean, and relative CFVR and stress echocardiography in intermediate-severity stenoses. The results of exercise or dobutamine stress echocardiography and CFVR measured by intracoronary Doppler were compared in 28 patients referred for assessment of intermediate-severity stenoses, using 15 patients with either angiographically normal coronary arteries or diameter stenoses > 70% as reference groups. CFVR was measured at least three times in response to a bolus of adenosine in the target vessel distal to the stenosis. RCFVR (target/normal vessel CFVR) was also measured in 27 patients. Maximal, mean (of three measures), and relative CFVR were calculated. CFVR > or = 2.0 and RCFVR > or = 0.75 were accepted as normal. A minority (29%) of patients in the intermediate-severity stenosis group had a positive test by either method. There was good to very good agreement between stress echocardiography and maximal CFVR (84%, kappa = 0.62, P < 0.0001) and RCFVR (81%, kappa = 0.59, P < 0.001) across the entire patient cohort, though in the intermediate subgroup concordance was only fair. Using the mean (of three measures of) CFVR for the same comparison improved the agreement in the intermediate subgroup to good (86%, kappa = 0.58, P = 0.002), and in the entire cohort the agreement was very good (88%, kappa = 0.74, P < 0.0001). There was only fair correlation between measures of CFVR and percent coronary stenosis. CFVR improved from 1.8 +/- 0.8 to 2.7 +/- 0.7 after percutaneous intervention (n = 12, P < 0.0001). These results suggest that there is good agreement between CFVR and stress echocardiography across a wide range of coronary lesion severity. The mean of three CFVR measurements distal to the target vessel stenosis increases diagnostic accuracy. Intracoronary Doppler flow velocity measurements at the time of cardiac catheterization may facilitate improved decision-making by providing the ability to assess the functional significance of coronary stenoses on-line.

Cobrahead malformation of the Amplatzer septal occluder device: an avoidable compilation of percutaneous ASD closure.

During deployment of an Amplatzer atrial septal occluder device to close a secundum ASD, the right atrial disk and waist of the device twisted, resulting in the cobrahead malformation. Postulated mechanisms for this complication include twisting of the device during loading into the delivery catheter and catching of leading edge of the device on the LA free wall or appendage, causing twisting during deployment. Retrieval of the device into the catheter and even removal of the device from the patient to allow manual untwisting may be required to allow the device to return to its original conformation for successful redeployment.

Thrombus on an ASD closure device: a call for caution.

Use of per-catheter atrial septal defect closure devices is becoming increasingly widespread. We report a case of left atrial thrombus formation on a StarFLEX device raising concerns regarding the general use of these devices and as a means of preventing paracloxical embolism in particular.

Chiari network entanglement and herniation into the left atrium by an atrial septal defect occluder device.

The Chiari network is a fenestrated membrane consisting of threads and strands in the right atrium. First described in 1897 by anatomist Hans Chiari, it is a congenital remnant of embryonic development resulting from incomplete resorption of the right valve of the sinus venosus. Found in 2% to 3% of the population, it is generally not of clinical importance. Rarely, however, the network may be associated with serious complications such as thrombus formation, embolus entrapment, arrhythmia, tumor development, and catheter entrapment. We report the entanglement of an Amplatzer septal occluder device catheter in a prominent Chiari network that was herniated into the left atrium. Transesophageal echocardiographic recognition of this before deployment and guidance during disentanglement is described below.

Unstable angina pectoris.

In recent years, there have been considerable advances in our understanding of the complex pathophysiology of unstable angina. A number of therapeutic options are now available. This article reviews current concepts of pathophysiology and summarises clinical features, natural history and available treatments.

Comparison of diltiazem and nifedipine alone and in combination in patients with coronary artery spasm.

Fifteen patients with coronary artery spasm completed a double-blind placebo-controlled trial comparing diltiazem and nifedipine. Increasingly, higher daily doses (diltiazem, 90 to 360 mg; nifedipine, 30 to 120 mg) were administered to achieve optimal clinical effects. Daily diaries and ambulatory electrocardiographic recordings were used to assess efficacy and side effects. Both drugs significantly decreased angina frequency compared with that in the preceding placebo period (diltiazem 1.4 +/- 0.4 [mean +/- SEM] to 0.4 +/- 0.2 episodes per day; nifedipine 1.4 +/- 0.3 to 0.4 +/- 0.1 episodes per day; both p less than 0.05). Ambulatory electrocardiographic recordings showed fewer ST shifts than were expected during all treatment periods (0.02/h recorded during placebo, none during diltiazem and 0.02/h during nifedipine therapy). Although some patients responded better to one drug than the other, neither drug resulted in a clearly superior clinical response. Diltiazem was discontinued in one patient because of urticaria, but the total number of side effects was higher with nifedipine (12 of 15 patients) than with diltiazem (5 of 15, p less than 0.01). Nine patients remained symptomatic on single drug treatment and entered open label treatment with the combination of diltiazem and nifedipine. Three patients did not tolerate the combination because of important side effects; the other six also had side effects, but these were relatively minor. Four patients received no more benefit from the combination than from a single agent; the condition of two patients improved. Both diltiazem and nifedipine provide effective antianginal therapy for coronary spasm, but diltiazem has fewer side effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Nicardipine for angina pectoris at rest and coronary arterial spasm.

The antiischemic effects and safety of nicardipine were assessed in 17 patients with angina at rest and coronary arterial spasm in a randomized placebo-controlled study over 8 to 13 weeks. Eleven patients had previously had unsatisfactory results with long-acting nitrates or other calcium blockers. The average daily dosage of nicardipine for optimal angina relief was 89 mg (range 40 to 160). During the double-blind phase, angina frequency decreased with nicardipine compared with placebo (mean 0.47 vs 2.11 attacks/day, p less than 0.05). A similar decrease in nitroglycerin requirements occurred (0.51 vs 2.77 tablets/day, p less than 0.05). During placebo periods, 51 episodes of ischemic ST-segment shifts occurred during 482 hours of ambulatory electrocardiographic monitoring and 12 (24%) were associated with angina. During nicardipine treatment, only 15 episodes of ST-segment shifts occurred during 498 hours of monitoring. In 1 patient a burning skin rash developed; otherwise, the drug was generally well tolerated. Thus, nicardipine is effective and safe in preventing symptomatic and asymptomatic ischemia in patients with coronary spasm. It may be particularly beneficial in patients with unsatisfactory responses to other therapy.

Prevention of vasospastic angina with nicardipine.

Anti-ischaemic effects and safety of nicardipine were assessed in 14 patients with vasospastic angina using a placebo comparison, cross-over design study for 8-13 weeks. The average daily dose of nicardipine for optimal angina prevention was 84 mg (range 40-160 mg). Nicardipine administration, as compared with placebo, significantly reduced anginal frequency and nitroglycerin consumption during the single- and double-blind phases of the study. Nicardipine appears to be effective in the prevention of vasospastic angina and not to cause major adverse effects.

Hemodynamic effects of nitroglycerin combined with diltiazem in patients with coronary artery disease.

Resting coronary and left ventricular hemodynamic effects of diltiazem and nitroglycerin, given intravenously in combination, were studied in 12 patients with coronary heart disease. Results observed with this combination were compared with those in seven patients given diltiazem initially (group I) and five patients given nitroglycerin initially (group II). The diltiazem-nitroglycerin combination reduced systolic blood pressure 27 percent (p less than or equal to 0.05) with no significant change in heart rate to affect a 22 percent (p less than or equal to 0.05) decrease in the rate-pressure product. Left ventricular end-diastolic pressure (-36 percent) and dp/dt (-6.4 percent) both declined (p less than or equal to 0.05). Coronary flow and cardiac output were both maintained. Diltiazem alone and nitroglycerin alone also reduced systolic pressure and the rate-pressure product but to a lesser degree than the combination. Diltiazem did not significantly affect left ventricular end-diastolic pressure and dp/dt. Nitroglycerin reduced left ventricular end-diastolic pressure to an extent similar to the reduction produced by the combination but increased heart rate whereas this determinant of myocardial oxygen demand did not increase significantly with the combination. These findings suggest that the combination of diltiazem and nitroglycerin produces a greater reduction in myocardial oxygen demand than either drug alone. In addition, the combination maintains coronary blood flow without increases in determinants of myocardial oxygen demand. This potentially beneficial drug combination warrants further trial in patients with myocardial ischemia.