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Biomedical subjects

L Bolognese

Publications and source records attributed to L Bolognese.

At least 73 records · Page 4Linked to original sources
PubMed1991

Early assessment of coronary artery bypass graft patency by high-dose dipyridamole echocardiography.

To assess the role of high-dose (up to 0.84 mg/kg during 10 minutes) dipyridamole echocardiographic testing in the evaluation of coronary artery bypass graft patency early after surgery, 18 consecutive patients with angina underwent dipyridamole echocardiography and coronary angiography before and 7 to 10 days after bypass surgery. Coronary angiography showed 2- or 3-vessel disease in 7 and 11 patients, respectively. A total of 53 bypass grafts were performed. Before bypass surgery 14 patients had a positive and 4 a negative test result. No complication occurred during the test performed early after surgery. Of the 14 patients with positive dipyridamole echocardiographic results before surgery, 10 had negative and 4 had positive results after surgery. All 4 patients had negative results before and after surgery. In the 4 patients with positive results after dipyridamole echocardiographic testing before and after bypass surgery, dipyridamole time increased from 5.8 +/- 5 to 9.3 +/- 0.9 minutes (p = 0.3) after the procedure and wall motion score index at peak dipyridamole changed from 1.55 +/- 0.2 to 1.28 +/- 0.3 (p = 0.05). Forty-nine of 53 grafts were patent as seen on angiography. Dipyridamole echocardiographic results were positive in 4 of 5 patients who had at least 1 obstructed graft or native vessel obstructed distal to bypass graft insertion. The remaining patient had diagnostic electrocardiographic changes during dipyridamole infusion without wall motion abnormalities. Dipyridamole echocardiographic results were negative in all 13 patients who had complete revascularization. In the 4 patients with positive test results, the procedure correctly identified the localization of the diseased bypass graft.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1991

Inhibition of dipyridamole-induced ischemia by antianginal therapy in humans. Correlation with exercise electrocardiography.

BACKGROUND: Dipyridamole echocardiography test (DET: two-dimensional echocardiographic monitoring with dipyridamole infusion up to 0.84 mg/kg in 10 minutes) is a useful tool for the noninvasive diagnosis of coronary artery disease. Aims of the present study were to assess the effects of antianginal drugs on dipyridamole-induced ischemia and to evaluate whether drug-induced changes in DET response may predict variations in exercise tolerance. METHODS AND RESULTS: Fifty-seven patients with angiographically assessed significant coronary artery disease (greater than 70% lumen reduction in at least one major coronary vessel) performed a DET and an exercise electrocardiography test (EET) in random order both off treatment and on antianginal drugs (beta-blockers, calcium antagonists and nitrates, alone or in various combinations). The criterion for DET positivity was a transient dyssynergy of contraction absent or of a lesser degree in the baseline examination. In DET, two parameters were evaluated: the dipyridamole time (i.e., the time from onset of dipyridamole infusion to obvious dyssynergy) and the wall motion score index. DET sensitivity was 91% off therapy and fell to 65% under therapy (p less than 0.01). In the 37 patients who had a positive DET both off and on therapy, the dipyridamole time increased from 6 +/- 3 (off therapy) to 8 +/- 3 minutes (on therapy) (p less than 0.01). The wall motion score index at peak dipyridamole went from 1.38 +/- 0.14 to 1.31 +/- 0.14 (p less than 0.01). EET and DET yielded concordant (positive versus negative) results in 41 of 57 (71%) patients off and in 35 of 57 (61%) on therapy (p = NS). In the subgroup of 38 patients with both positive DET and EET without treatment, the therapy-induced variations in exercise time were significantly correlated with the variations in dipyridamole time (r = 0.5; p less than 0.01), not with variations in wall motion score index (r = 0.3; p = NS). CONCLUSIONS: 1) Antianginal therapy can protect from dipyridamole-induced ischemia and 2) the therapy-induced changes in DET response parallel variations in exercise tolerance and might be useful for the objective, exercise-independent assessment of the therapy efficacy.

Adrenergic beta-Antagonists↗
PubMed1991

Dipyridamole echocardiography test. A new tool for detecting jeopardized myocardium after thrombolytic therapy.

BACKGROUND: We wished to assess whether dipyridamole echocardiography test (DET) can detect jeopardized myocardium after thrombolytic therapy. METHODS AND RESULTS: Seventy-six consecutive patients with a first acute myocardial infarction (AMI) were treated with 2 million IU urokinase i.v. within 4 hours of the onset of AMI and underwent high-dose (as much as 0.84 mg/kg over 10 minutes) DET 8-10 days after AMI. The results were correlated to the anatomy of the infarct-related vessel (IRV). In patients with positive DET, we evaluated the wall motion score index (WMSI; a semiquantitative integrated estimation of extent and severity of the stress-induced dyssynergy). WMSI was derived by summation of individual segment scores divided by the number of interpreted segments. In a 13-segment model, each segment was assigned a score ranging from 1 (normal) to 4 (dyskinetic). Fifty-three patients had positive results on DET. Of these, 42 had dipyridamole-induced new wall motion abnormalities (WMAs) confined to the infarct zone or adjacent segments. In these patients, mean WMSI increased from 1.46 +/- 0.26 (at resting conditions) to 1.73 +/- 0.35 (at peak dipyridamole) (p less than 0.01), whereas no significant change was detected in negative patients (1.6 +/- 0.34 versus 1.57 +/- 0.34, p = NS). Coronary angiography showed a patent IRV (TIMI grade 2 or 3) in 53 patients and no or minimal reperfusion (TIMI grade 0 or 1) in 23 patients. A patent IRV with critical residual stenosis was found in 35 of 42 patients with dipyridamole-induced WMAs in the infarct zone and in 18 of 34 patients without WMAs (p less than 0.05). Among the 23 patients with occluded IRVs, nine had collateral flow to the distal vessel; six of these had a positive DET. Thus, the sensitivity and specificity for identifying a critically stenotic but patent IRV or the presence of a collateral-dependent zone were 66% and 93%, respectively. In a subset of nine patients with a positive DET in the infarct zone or adjacent segments, DET and a control coronary angiography were repeated 1-3 months after an angiographically successful (residual stenosis, 50% or less) coronary angioplasty in the IRV. The repeat DET was negative in eight patients (all with patent IRV at control angiography) and again positive in one patient, who showed restenosis at angiography. The WMSI, at resting conditions was similar before and after angioplasty, whereas it differed significantly at peak dipyridamole (1.7 +/- 0.2 versus 1.4 +/- 0.2, p less than 0.01). CONCLUSIONS: DET can identify the anatomy of the IRV, and dipyridamole-induced WMAs within the infarct zone detect regions with jeopardized myocardium that may benefit from intervention.

Coronary Angiography↗
PubMed1991

[The echo-dipyridamole test early after acute myocardial infarct: echocardiographic aspects and angiographic correlations].

To assess whether the different mechanical effects of intravenous dipyridamole were correlated with the location and distribution of the coronary arteries stenosis, 98 patients underwent high dose DET 8-10 days after an acute myocardial infarction. Left ventricular regional wall segments were identified in multiple views; a vascular territory was assigned to each coronary vessel. DET was positive in 68.4% of the patients (67/93), 59% (23/39) of those with single vessel disease, and 81% (44/54) of those with multivessel disease. Four different mechanical patterns of positivity of DET were observed: 1) marked worsening of wall motion in the same region showing asynergy (type I); 2) development of new wall motion abnormality adjacent to the infarct zone and located in the same vascular region (type II); 3) development of new wall motion abnormality adjacent to the infarct zone, but located in a different vascular region (type III); 4) development of transient remote asynergy (that is, a new wall motion abnormality in a region normal at rest and not directly adjacent to the infarct zone, type IV). Types I and II (asynergies in the infarct zone coronary bed) were found in patients both with single vessel disease or multivessel disease; by contrast, type III and IV were almost exclusively found in patients with multivessel disease (24/54 and 14/54 respectively) and occasionally in patients with single vessel disease (2/39 and 1/39 respectively). Thus, these two mechanical behaviours during dipyridamole infusion showed to be highly specific for predicting multivessel disease (95% and 97% respectively, sensitivity 44% and 26% respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Stress testing in the period after infarction.

Dipyridamole echocardiography is gaining popularity as an exercise-independent diagnostic method in patients with suspected or demonstrable coronary artery disease. To assess its safety, feasibility, and diagnostic accuracy in patients recovering from uncomplicated acute myocardial infarction, 131 patients had the test before hospital discharge. The results were compared with those of maximum treadmill testing. We found that dipyridamole-induced transient asynergy remote from the infarct zone was more sensitive (74% versus 53%, p less than 0.05) and specific (97% versus 68%, p less than 0.01) than treadmill testing for detecting multivessel coronary artery disease. In a subgroup of 42 patients treated with thrombolytic therapy, dipyridamole echocardiography was able to detect in 27 the presence of jeopardized but viable myocardium in the infarct zone. An excellent correlation was found between dipyridamole echocardiography responses and infarct vessel patency. Finally, the prognostic impact of dipyridamole echocardiography on patients recovering from acute myocardial infarction was assessed in a consecutive series of 151 patients. Eighteen months of event-free survival was significantly different in patients with positive versus negative dipyridamole echocardiography results (76.1% versus 50.8%, p less than 0.01). The test was also superior to treadmill testing in predicting cardiac events. Thus, dipyridamole echocardiography performed early after acute myocardial infarction is safe, feasible, and accurate for predicting the extent of coronary artery disease and 18-month clinical outcome.

Coronary Disease↗
PubMed1990

Lack of influence of atrioventricular delay on stroke volume at rest in patients with complete atrioventricular block and dual chamber pacing.

Dual chamber pacing (DDD) maintains atrioventricular (AV) sequence; AV delay programmability modifies the relationship between atrial and ventricular contraction. To evaluate the hemodynamic effects of such a modification, ten patients with a DDD unit for complete AV block were studied by time-motion (M-mode) and Doppler echocardiography during inhibited ventricular pacing (VVI), atrial-triggered ventricular pacing (VDD) and atrioventricular sequential pacing (DVI) at different AV delay (90, 140, 190, 240 msec). A significant improvement in stroke volume (SV) (15%-20%, P less than 0.05) was seen during DDD versus VVI pacing; no changes, however, were observed in the same patient with different AV delay or during DVI versus VDD pacing. These data suggest that programming of AV delay does not affect systolic performance at rest; longer diastolic filling times recorded during DDD pacing with "short" AV delay (90-140 msec) do not seem to be a hemodynamically relevant epi-phenomenon of PM programming.

Aged↗
PubMed1990

[Late potentials and computerized averaging electrocardiogram in acute myocardial infarct: evaluation of myocardial reperfusion].

Myocardial reperfusion after thrombolytic therapy in acute myocardial infarction can be directly demonstrated with coronary angiography or it can be assessed thanks to indirect markers of reperfusion, such as modifications in the "averaged" QRS complex. We assessed the presence of late potentials in 37 patients within 5 hours of acute myocardial infarction onset and evaluated their disappearance or modification after reperfusion. Signal-averaged electrocardiogram, obtained computerizing QRS complexes filtered through Simson's bidirectional filter (25-250 Hz), was serially recorded in each patient: at admission, as well as 12 hours, 3 and 10 days following urokinase and/or heparin therapy. Other indirect markers of reperfusion (incidence of ventricular arrhythmias, serum CK-MB level, ST elevation) were contemporaneously evaluated. All patients underwent coronary angiography between 6 and 83 days after acute myocardial infarction. Late potentials (Total QRS greater than 115 ms; Under 40 microV greater than 39 ms; RMS Last 40 ms less than 25 microV) were present only in 25% of patients, and they always disappeared after successful thrombolysis. On the contrary if ischemia-related vessel occlusion persisted, late potentials persisted as well or else were first recorded on the 3rd or 10th day following acute myocardial infarction. Quantitative analysis of the "averaged" QRS complex showed a statistically significant reduction in QRS duration (-9.1 +/- 12.7 ms) 3 days after acute myocardial infarction in reperfused patients (group A, n = 24), while no significant reduction in the total QRS (-1 +/- 6.7 ms) was observed in non-reperfused cases (group B, n = 13), (p less than 0.05 group A vs group B). So, 10 ms reduction in total QRS duration was a good marker of reperfusion, with specificity = 92% and sensitivity = 54%; marker sensitivity was even higher (= 79%) when coupled with serum CK-MB peak within 12 hours of therapy (diagnostic accuracy = 84%). In conclusion, even if late potentials have a low prevalence in acute myocardial infarction (25%) their disappearance correlates with myocardial reperfusion. Furthermore, a reduction in total QRS duration greater than or equal to 10 ms can itself be a good marker of successful thrombolysis.

Adult↗
PubMed1989

High dose dipyridamole echocardiography early after uncomplicated acute myocardial infarction: correlation with exercise testing and coronary angiography.

The feasibility, safety and usefulness of dipyridamole echocardiography (two-dimensional echocardiography and 12 lead electrocardiographic monitoring during dipyridamole infusion, up to 0.84 mg/kg over 10 min) were evaluated in 94 asymptomatic patients 8 to 10 days after uncomplicated acute myocardial infarction. The results were compared with those of symptom-limited treadmill exercise testing and correlated with coronary angiography. Two mechanical patterns of positivity of dipyridamole echocardiography could be identified: 1) a new wall motion abnormality confined to the infarct zone or to the adjacent segments (24 patients), and 2) transient remote asynergy (33 patients). The success rate in recording adequate images during dipyridamole infusion was 100%. Interobserver agreement concerning diagnosis occurred in 89 (93%) of 94 patients. Dipyridamole echocardiography was well tolerated; no complication was observed during or after the test. Seventy-three patients underwent coronary angiography within 6 weeks after acute myocardial infarction. Transient remote asynergy on echocardiography was present in 27 of 40 patients with multivessel disease and in none of 33 patients without multivessel disease. Results of treadmill exercise testing were positive in 28 patients with multivessel disease and 8 patients without multivessel disease. Thus, the sensitivity of dipyridamole-induced transient remote asynergy was 68% compared with 52% for treadmill testing (p less than 0.05); specificity was 100% and 72%, respectively (p less than 0.005). The overall accuracy of dipyridamole echocardiography (81%) was higher than that of dipyridamole stress electrocardiography (63%) or exercise electrocardiography (60%) (p less than 0.02). It is concluded that dipyridamole echocardiography is a useful, feasible and inexpensive nonexercise-dependent test for detecting the extent of coronary artery disease early after acute myocardial infarction.

Adult↗
PubMed1988

Sustained beneficial hemodynamic effects of low transdermal nitroglycerin doses compared with placebo in patients with congestive heart failure.

In an attempt to resolve some of the controversies concerning the dose requirements and duration of effects of transdermal nitroglycerin (NTG) in patients with heart failure (CHF), the short-term hemodynamic responses to transdermal NTG, in a 20 cm2 self-adhesive patch (10 mg/24 h), were evaluated in 10 patients with severe chronic CHF using a randomized, within-patient, double-blind, placebo-controlled cross-over trial. Serial hemodynamic measurements over 24 h revealed sustained effects that began 1 h after the application of nitroglycerin patch and fully persisted throughout the study. The peak effect occurred at 4 h with the pulmonary capillary wedge pressure decreasing from 33.7 +/- 8.4 to 21.4 +/- 9 mmHg (mean +/- SD) (p less than 0.05) and the cardiac index increasing from 2.5 +/- 0.6 to 3 +/- 0.6 l/min/m2 (p less than 0.01). Transdermal nitroglycerin also significantly reduced pulmonary arterial and right atrial pressures (from 43.5 +/- 9.5 to 31 +/- 11.4 and from 7.4 +/- 6.6 to 3.8 +/- 4.7 at peak effect, respectively) as well as pulmonary and systemic vascular resistances (from 10.7 +/- 6.6 to 6.5 +/- 3.2 and from 26.2 +/- 5.1 to 22.5 +/- 5.7, respectively). There was no change in heart rate or systemic arterial pressure. These beneficial hemodynamic responses persisted for 24 h. No rebound deterioration occurred upon withdrawal of the nitroglycerin. No significant hemodynamic changes occurred during placebo treatment period. Thus, low doses (10 mg/24 h) of transdermal nitroglycerin induce significant hemodynamic benefit that is sustained for 24 h in patients with heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1988

Angiographic morphology and response to therapy in unstable angina.

The coronary anatomy of 69 patients with unstable angina, subgrouped according to response to medical therapy, was investigated. All patients received oral treatment with nitrates, calcium antagonists, and beta-blocking agents. When combined oral treatment was not effective, an intravenous infusion of nitrates (10-100 micrograms/min) was subsequently administered. Coronary arteriography was performed within hours (14 +/- 9 h) from the last episode of chest pain in 28 patients refractory to medical treatment, while in 41 patients who became asymptomatic during medical therapy, angiography was performed after an observation period of several days (8 +/- 6 days). On angiography, the nonresponder group was characterized by a prevalence of eccentric and multiple lesions, and by a 46% incidence of thrombi (p less than 0.001). Recurrent symptoms requiring emergency bypass operation were common in this group. In patients responsive to medical treatment, a high percentage of concentric lesions (37%) and totally occluded (34%) coronary arteries was found (p less than 0.05). No infarcts and low rate of recurrent angina were noted in these patients during hospitalization. In conclusion, the finding of intracoronary thrombotic material and eccentric or multiple lesions can be an accurate markers of the active phase of the disease, while "silent" occlusion of the involved vessel may be accompanied by relief of symptoms during medical therapy.

Adrenergic beta-Antagonists↗
PubMed1988

Respiratory-dependent atrial pacing, management of sinus node disease.

The effectiveness of respiratory-dependent atrial pacing (AAI-RD) was assessed in 23 patients (11 male, 12 female; 68 +/- 10 years) with symptomatic isolated sinus node disease (SND). Follow-up was performed at 3 month intervals and included history taking, physical examination, ECG recording and 24-hour Holter monitoring. An incremental treadmill exercise test was performed in 21/23 patients before pacemaker implantation, in 23/23 patients after implantation (at least two tests with different programmed settings of respiratory rate/paced rate ratio); 21/23 patients underwent treadmill tests during both fixed rate 70 bpm and AAI-RD pacing. Physiological sensitivity of AAI-RD pacing was found excellent in 34 tests (85%) and fair in six (15%). Spontaneous heart rate was significantly higher after pacemaker implantation (bpm 115 +/- 20 vs 98 +/- 24, P less than 0.001). In 10/21 patients paced rate was significantly higher during AAI-RD vs AAI pacing (131 +/- 9 vs 106 +/- 16, P less than 0.001) with better total work time (min 9.9 +/- 4 AAI-RD vs 6.8 +/- 2.6 AAI, P less than or equal to 0.002), higher oxygen consumption at anaerobic threshold (ml/min 1137 +/- 406 AAI-RD vs 882 +/- 268 AAI-RD vs 5.5 +/- 2.6 AAI, P = 0.001). No significant difference was found in 7/21 patients (overlap between spontaneous and paced rate during both AAI-RD and AAI programming); 4/21 patients did not reach anaerobic threshold owing to osteomuscular limitations. AV block was detected in 1/23 patients, Biorate circuital failure in 1/23, sporadic undersensing in 5/23, short and symptom-free myopotential inhibitions in 10/23.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗