The growing role of echocardiography in interventional cardiology: The present and the future.

As structural heart disease interventions continue to evolve to a sophisticated level, accurate and reliable imaging is required for pre-procedural selection of cases, intra-procedural guidance, post-procedural evaluation, and long-term follow-up of patients. Traditionally, cardiovascular procedures in the catheterization laboratory are guided by fluoroscopy and angiography. Advances in echocardiography can overcome most limitations of conventional imaging modalities and provide successful completion of each step of any catheter-based treatment. Echocardiography's unique characteristics rendered it the ideal technique for percutaneous catheter-based procedures. The purpose of this review is to demonstrate the use of the most common and up-to-date echocardiographic techniques in recent non-coronary percutaneous interventional procedures, underlining its inevitable and growing role, as well as illustrating areas of weakness and limitations, and to provide future perspectives.

Blood pressure response to catheter-based renal sympathetic denervation in severe resistant hypertension: data from the Greek Renal Denervation Registry.

BACKGROUND/INTRODUCTION: The efficacy of catheter-based renal sympathetic denervation (RDN) in terms of blood pressure (BP) reduction has been questioned, while "real-world" data from registries are needed. In this study, we report the complete set of 12-month data on office and ambulatory BP changes as well as the predictors for BP response to RDN from a national registry. METHODS: In 4 Greek hospital centers, 79 patients with severe drug-resistant hypertension (age 59 ± 10 years, 53 males, body mass index 33 ± 5 kg/m2; office BP and 24-h ambulatory BP were 176 ± 15/95 ± 13 and 155 ± 14/90 ± 12 mmHg, respectively, 4.4 ± 0.9 antihypertensive drugs) underwent RDN and were followed-up for 12 months in the Greek Renal Denervation Registry. Bilateral RDN was performed using percutaneous femoral approach and standardized techniques. RESULTS: Reduction in office systolic/diastolic BP at 6 and 12 months from baseline was -30/-12 and -29/-12 mmHg, while the reduction in 24-h ambulatory BP was -16/-9 and -15/-9 mmHg, respectively (p < 0.05 for all). Patients that were RDN responders (85%, n = 58), defined as an at least 10-mmHg decrease in office systolic BP at 12 months, compared to non-responders were younger (57 ± 9 vs 65 ± 8 years, p < 0.05), had higher baseline office systolic BP (176 ± 17 vs 160 ± 11 mmHg, p < 0.05) and 24-h systolic BP (159 ± 13 vs 149 ± 11 mmHg, p < 0.05). Stepwise logistic regression analysis revealed that age, obesity parameters, and baseline office BP were independent predictors of RDN response (p < 0.05 for both), but not the type of RDN catheter or the use of aldosterone antagonists. At 12 months, there were no significant changes in renal function and any new serious device or procedure-related adverse events. CONCLUSIONS: In our "real-world" multicenter national registry, the efficacy of renal denervation in reducing BP as well as safety is confirmed during a 12-month follow-up. Moreover, younger age, obesity, and higher levels of baseline systolic BP are independently related to better BP response to RDN.

Effect of acute atrial fibrillation on phasic coronary blood flow pattern and flow reserve in humans.

AIMS: To assess the effect of experimentally induced atrial fibrillation on coronary flow in humans. METHODS AND RESULTS: In 16 patients (10 men, mean age 43+/-13 years) with normal coronary vessels, baseline and hyperaemic blood pressure and Doppler phasic coronary flow velocity were measured, using a 0.014 inch intracoronary Doppler flow wire, during sinus rhythm, experimentally induced atrial fibrillation, and right atrial pacing at a similar heart rate to that during atrial fibrillation. Coronary flow velocity integral per minute increased significantly during both right atrial pacing and atrial fibrillation compared to sinus rhythm, but during right atrial pacing the increase was greater (85+/-43% vs 52+/-25%, P<0.001). This difference persisted even after correction for the product of heart rate and blood pressure (1.15+/-0.51 vs 0.97+/-0.46, respectively, P<0.02). In a further 12 paced patients (seven men, mean age 54+/-10 years) with complete atrioventricular block the induction of atrial fibrillation (atrial fibrillation with regular RR interval) caused no significant changes in coronary flow velocity variables. CONCLUSIONS: Acute atrial fibrillation in humans causes an increase in coronary flow that is, however, insufficient to compensate for the augmented myocardial oxygen demand, mainly because of the irregularity in the ventricular rhythm that exists during atrial fibrillation.

Electrocardiographic diagnosis of acute myocardial infarction in the presence of ventricular paced rhythm.

ST-segment deviation was recently described as the only ECG finding that was useful in the diagnosis of acute myocardial infarction during right ventricular pacing. This report shows that the same sign may also indicate the amount of myocardium in jeopardy and the coronary artery responsible.

Myocardial perfusion in patients with permanent ventricular pacing and normal coronary arteries.

OBJECTIVES: The purposes of this study were to test the specificity of dipyridamole myocardial perfusion scintigraphy in patients with permanent ventricular pacing (PVP) and to evaluate coronary blood flow and reserve in these patients. BACKGROUND: Permanent ventricular pacing is associated with exercise perfusion defects on myocardial scintigraphy in the absence of coronary artery disease (CAD). On the basis of studies in patients with left bundle brunch block, coronary vasodilation with dipyridamole has been proposed as an alternative to exercise testing for detecting CAD in paced patients, but this approach has never been tested. METHODS: Fourteen patients with a PVP and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In these patients and in eight control subjects, coronary flow velocities were measured in the left anterior descending coronary artery (LAD) and in the dominant coronary artery before and after adenosine administration. RESULTS: In the paced patients, coronary flow velocities in the LAD and in the dominant coronary artery were significantly lower than those in the control subjects. In addition, seven patients showed perfusion defects on dipyridamole thallium-201 single-photon emission computed tomography, with a specificity of 50% for this test. The defect-related artery in these patients had lower coronary flow reserve (2.6 +/- 0.5) as compared with those without perfusion defects (3.9 +/- 1.0, p < 0.05) or the control group (3.5 +/- 0.5, p < 0.05). CONCLUSIONS: Permanent ventricular pacing is associated with alterations in regional myocardial perfusion. Furthermore, abnormalities of microvascular flow, as indicated by reduced coronary flow reserve in the defect-related artery, are at least partially responsible for the uncertain specificity of dipyridamole myocardial perfusion scintigraphy.

Aortic atherosclerotic lesions in the thoracic aorta detected by multiplane transesophageal echocardiography as a predictor of coronary artery disease in elderly patients.

BACKGROUND: The presence of atherosclerotic lesions in the thoracic aorta by transesophageal echocardiography (TEE) appears to be a marker for the presence of significant coronary artery disease (CAD) in the general population. HYPOTHESIS: We investigated whether atherosclerotic lesions in the thoracic aorta, by multiplane TEE, could be a marker for CAD in elderly patients. METHODS: In all, 127 patients (67 men, 60 women, aged 68 +/- 13 years), underwent a TEE study with imaging of the thoracic aorta and cardiac catheterization with coronary angiography. The presence of a distinct, linear, or focal, highly echogenic mass protruding into the vessel lumen was the criterion for the diagnosis of atherosclerotic plaque. RESULTS: Atherosclerotic lesions were found in 30 of 36 patients (83.3%) with and in 20 of 91 (22%) without CAD. Of the 41 patients > or = 70 years, atherosclerotic lesions were detected in 14 of 17 (82.3%) with and in 13 of 24 patients (54%) without CAD. The sensitivity, specificity, and positive and negative predictive values in this group were 82.3, 46, 52, and 78.6%, respectively. Multivariate logistic regression analysis revealed that in patients aged > or = 70 years only advanced atherosclerotic lesions were independent predictors of significant CAD. However, the high negative predictive value of the method indicates that the absence of aortic plaque is a strong predictor of the absence of CAD. CONCLUSIONS: The presence of atherosclerotic lesions in the thoracic aorta is a strong predictor of CAD only in patients < 70 years old. However, the negative predictive value of the method is high for all patients regardless of age.

Left ventricular diastolic filling pattern predicts cardiopulmonary determinants of functional capacity in patients with congestive heart failure.

BACKGROUND: Abnormalities of diastolic function are an important determinant of exercise intolerance in patients with heart failure. However, the relation between left ventricular filling pattern and cardiopulmonary exercise performance has not been adequately studied. METHODS: Thirty-one patients with idiopathic (n = 14) or ischemic (n = 17) dilated cardiomyopathy, demonstrated by coronary angiography, and radionuclide ejection fraction 30.5% +/- 9% underwent cardiopulmonary exercise testing with a modified Naughton protocol and a complete echocardiographic study. Patients were subdivided into restrictive and nonrestrictive groups according to their Doppler transmitral flow pattern. Gas exchange data were measured during exercise testing. The relation of left ventricular filling pattern to cardiopulmonary parameters was assessed in both groups. RESULTS: Exercise duration was similar in the restrictive and nonrestrictive groups but significant differences were found in oxygen consumption (VO(2)) at peak exercise (14.3 +/- 2.4 vs 20.4 +/- 4.7 mL/kg per minute; P <.001) and at the anaerobic threshold (VO(2AT)) (13 +/- 2.2 vs 17.3 +/- 3 mL/kg per minute; P <.001). Simple linear regression analysis revealed that both peak VO(2) and VO(2AT) were significantly correlated with the ratio of peak early (E wave) to late (A wave) transmitral filling velocity, early filling deceleration time, atrial filling fraction, and A-wave velocity but not with left ventricular ejection fraction. Multivariate regression analysis gave only the peak A-wave velocity as an independent predictor for both peak VO(2) and VO(2AT). CONCLUSIONS: In patients with heart failure, abnormalities of diastolic function are the most important determinant of exercise intolerance. A restrictive transmitral flow pattern by Doppler echocardiography is a marker of diminished cardiopulmonary exercise performance in these patients.

Effect of pericardial pressure on human coronary circulation.

A 52-year-old patient underwent percutaneous balloon pericardiotomy because of rapid fluid accumulation. During the procedure, we calculated the amount of blood flow to the nondiseased left anterior descending coronary artery while pericardial pressure was gradually increased by the infusion of warmed normal saline solution. Coronary vasodilator reserve was assessed by intracoronary adenosine. With increasing pericardial pressure, there was a continuous decline in coronary blood flow, due to an increase in coronary vascular resistance, and an unaffected hyperemic response throughout. The maximal hyperemic flow was far less under increased pericardial pressure than at normal pressure, which implies an augmented susceptibility to myocardial ischemia.

Assessment of left ventricular ejection dynamics in patients with coronary artery disease during dipyridamole-stress Doppler echocardiography.

OBJECTIVES: To investigate the contribution of Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole-stress to the diagnosis of coronary artery disease (CAD). DESIGN: This was a clinical study. METHODS: Echocardiographic studies under baseline and peak dipyridamole stresses were performed on 15 normal subjects and 32 patients with angiographically confirmed CAD. Peak Doppler velocity, acceleration, and acceleration time of the ascending aorta, as well as segmental left ventricular wall motion, were analyzed. RESULTS: The sensitivity, specificity and overall accuracy of wall-motion abnormalities induced by dipyridamole for the detection of CAD were 62.5, 100, and 74.5%, respectively. When wall-motion abnormalities were combined with the percentage changes in peak aortic velocity and acceleration, the overall sensitivities were 84.38 and 78.15%, respectively, the specificities were 66.7 and 80.00%, respectively, and the accuracy was 78.72% for both models. When all three parameters were combined, the sensitivity, specificity and overall accuracy of the method were 87.5, 86.7, and 87.2%, respectively. CONCLUSIONS: Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole stress could be a useful adjunct to two-dimensional echocardiography by improving its sensitivity in the diagnosis of CAD.

Pulmonary tumor embolism from primary cardiac B-cell lymphoma.

We report the case of a 54-year-old man with pulmonary embolism during convalescence from "idiopathic" pericarditis. A transthoracic echocardiographic examination indicated a large mass within the right atrium. Subsequently, he died from refractory hypotension. On autopsy, two large whitish nodules were found in the right atrium; there was also nodular epicardial infiltration. Both lungs showed multiple, grossly visible tumor emboli with pulmonary infarction and no evidence of conventional thromboembolism. This is the first report of pulmonary tumor embolism due to large cell B-cell primary cardiac lymphoma. Refractory unexplained pericardial effusion, pulmonary embolism without risk factors for venous thrombosis, and/or the existence of a mass in the right heart should arouse clinical suspicion for this rare malignancy.

Phasic coronary flow pattern and flow reserve in patients with left bundle branch block and normal coronary arteries.

OBJECTIVES: The purpose of this study was to determine whether scintigraphic myocardial perfusion defects in patients with left bundle branch block (LBBB) and normal coronary arteries are related to abnormalities in coronary flow velocity pattern and/or coronary flow reserve. BACKGROUND: Septal or anteroseptal defects on exercise myocardial perfusion scintigraphy are common in patients with LBBB and normal coronary arteries. METHODS: Thirteen patients (7 men, age 61+/-8 years) with LBBB and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In all patients and in 11 control subjects coronary blood flow parameters were calculated from Doppler measurements of flow velocity in the left anterior descending coronary artery (LAD) before and after adenosine administration. RESULTS: The time to maximum peak diastolic flow velocity was significantly longer both for the seven patients with (134+/-19 ms) and for the six without (136+/-7 ms) exercise perfusion defects than for controls (105+/-12 ms, p < 0.05), whereas the acceleration was slower (170+/-54, 186+/-42 and 279+/-96 cm/s2, respectively, p < 0.05). Coronary flow reserve in the patients with exercise perfusion defects (2.7+/-0.3) was significantly lower than in those without (3.7+/-0.5, p < 0.05) or in the control group (3.4+/-0.5, p < 0.05). CONCLUSIONS: Patients with LBBB have an impairment of early diastolic blood flow in the LAD due to an increase in early diastolic compressive resistance resulting from delayed ventricular relaxation. Furthermore, exercise scintigraphic perfusion defects in these patients are associated with a reduced coronary flow reserve, indicating abnormalities of microvascular function in the same vascular territory.

AAIR versus DDDR pacing in patients with impaired sinus node chronotropy: an echocardiographic and cardiopulmonary study.

The aim of this study was to compare AAIR and DDDR pacing at rest and during exercise. We studied 15 patients (10 men, age 65 +/- 6 years) who had been paced for at least 3 months with activity sensor rate modulated dual chamber pacemakers. All had sick sinus syndrome (SSS) with impaired sinus node chronotropy. The patients underwent a resting echocardiographic evaluation of systolic and diastolic LV function at 60 beats/min during AAIR and DDDR pacing with an AV delay, which ensured complete ventricular activation capture. Cardiac output (CO) was also measured during pacing at 100 beats/min in both pacing modes. Subsequently, the oxygen consumption (VO2AT) and VO2AT pulse at the anaerobic threshold were measured during exercise in AAIR mode and in DDDR mode with an AV delay of 120 ms. The indices of diastolic function showed no significant differences between the two pacing modes, except for patients with a stimulus-R interval > 220 ms, for whom the time velocity integral of LV filling and LV inflow time were significantly lower under AAI than under DDD pacing. At 60 beats/min, CO was higher under AAI than under DDD mode only when the stimulus-R interval was below 220 ms. For stimulus-R intervals longer than 220 ms, and also during pacing at 100 beats/min, the CO was higher in DDD mode. The stimulus-R interval decreased in all patients during exercise. The time to anaerobic threshold, VO2AT, and VO2AT pulse showed no significant differences between the two pacing modes. Our results indicate that, at rest, although AAIR pacing does not improve diastolic function in patients with SSS, it maintains a higher CO than does DDDR pacing in cases where the stimulus-R interval is not excessively prolonged. On exertion, the two pacing modes appear to be equally effective, at least in cases where the stimulus-R interval decreases in AAIR mode.

Effect of transdermal scopolamine on heart rate variability in patients with severe coronary heart disease.

A decrease in cardiac parasympathetic tone is a recognized finding in patients with ischemic heart disease, correlating closely with disease severity and overall survival. The aim of this study was to assess whether transdermal scopolamine (Tds), which increases parasympathetic tone in healthy volunteers, increases vagal tone in patients with severe CAD and whether it might have an antiischemic effect. Fifteen patients (10 men, aged 55 +/- 8 years) with three-vessel CAD, but with no prior MI and preserved ventricular function, underwent 24-hour Holter monitoring and exercise testing before and after wearing a scopolamine patch for 24 hours. Time-domain measures of heart rate variability (HRV) and the total number and duration of ischemic episodes were obtained from the Holter recordings for each patient. Tds significantly (P < 0.05) increased the values of all HRV measures. Tds also reduced the total number of ischemic episodes (from 273 to 159, P < 0.05) and their total duration (from 136 to 46 min per patient, P < 0.05). Tds also increased treadmill exercise duration from 293 +/- 101 to 345 +/- 95 seconds (P < 0.05) and the time to 1-mm ST depression from 177 +/- 105 to 244 +/- 128 seconds (P < 0.02), while maximum ST depression was reduced from 2.86 +/- 0.6 to 2.3 +/- 0.3 (P < 0.05). No significant side effects were observed. Tds modifies the autonomic balance in patients with severe CAD toward a condition associated with a better prognosis. It may also be useful as an adjunctive treatment for ischemic heart disease.

Twenty four hour variation in plasma atrial natriuretic factor during VVI and DDD pacing.

OBJECTIVE: To investigate whether plasma atrial natriuretic factor (ANF) follows a pattern of circadian variation similar to that of other hormones in patients paced under VVI and DDD pacing modes and to determine if the known effect of pacing mode on ANF secretion is maintained throughout the 24 hour period. PATIENTS AND DESIGN: 20 patients were studied. They had complete atrioventricular block and had been paced for 17 (SD 3.5) months with a dual chamber multiprogrammable pacemaker. They were divided into two groups according to the duration of pacing in either VVI or DDD mode before the measurements: group A, n = 11 (8 men, 3 women, aged 65 (7) years), each paced for 24 h under each of VVI and DDD modes in random order; group B, n = 9 (7 men, 2 women, aged 63 (8) years), each paced for 60 d under each pacing mode before the measurements. Blood samples were taken and ANF concentrations measured every 4 h over a 24 h period, starting at 09.00. Measurements were also made of plasma cortisol, which has a known circadian pattern, so that the 24 h curve could be compared with that of ANF. RESULTS: In contrast to cortisol, ANF values indicated a pulsatile pattern of secretion throughout the 24 h period, with no clear circadian variation. In group B, ANF concentrations were significantly higher during VVI than during DDD pacing throughout the 24 h period, whereas in group A this difference was statistically significant only at certain times of day. CONCLUSIONS: ANF does not show the circadian pattern of variation shown by cortisol and other hormones. Dual chamber pacing contributes to an improvement not only in cardiac haemodynamics but also in the neuroendocrine system, especially in the long term.

Absence of atherosclerotic lesions in the thoracic aorta indicates absence of significant coronary artery disease.

Atherosclerotic lesions may be readily visualized in the thoracic aorta using transesophageal echocardiography. The absence of aortic plaque in the thoracic aorta rules out significant coronary artery obstruction whereas the existence of the former appears to be a sensitive and specific predictor of the latter.

Impact of atrioventricular delay on heart rate variability of paced patients with and without heart failure.

The aim of the study was to investigate whether the optimisation of atrioventricular (AV) delay in patients with complete AV block, with or without heart failure, paced under VDD mode, has an effect on heart rate variability and consequently on the autonomic nervous system in these patients. We studied 10 patients (Group I: 7 men, aged 68 +/- 9 years) with normal left ventricular function and 9 patients (Group II: 6 men, aged 70 +/- 6 years) with systolic left ventricular dysfunction (NYHA heart failure Class II or III). Each patient was paced for 24 h with the optimal and 24 h with the worst AV delay in random order and ambulatory electrocardiograms (ECGs) (Marquette) were recorded. Spectral heart rate variability was analysed for each 24-h period on a Holter analysis system (Marquette Series 8000). The optimal and worst AV delay were determined by echo-Doppler as those which produced the greatest and least cardiac output, respectively. For the patients in Group I, there was no difference between the two AV delays as regards indices of heart rate variability. In contrast, for Group II the total frequency (TF) was significantly higher and the low frequency (LF) and LF/high frequency (HF) ratio were significantly lower when the patients were paced with optimum AV delay. Furthermore, this AV delay resulted in significantly higher mean NN and SD. In conclusion, in patients with normal left ventricular function, changes in AV delay do not appear to affect the activity of the autonomic nervous system in the heart. In patients with mild to moderate heart failure, optimisation of the AV delay causes a significant drop in sympathetic nervous tone.