Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures.

Despite the advent of non-fluoroscopic technology, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies over ablation interventions to device implantation. Moreover, many patients receive additional X-ray imaging, such as cardiac computed tomography and others. More and more complex procedures have the risk to increase the radiation exposure, both for the patients and the operators. The professional lifetime attributable excess cancer risk may be around 1 in 100 for the operators, the same as for a patient undergoing repetitive complex procedures. Moreover, recent reports have also hinted at an excess risk of brain tumours among interventional cardiologists. Apart from evaluating the need for and justifying the use of radiation to assist their procedures, physicians have to continuously explore ways to reduce the radiation exposure. After an introduction on how to quantify the radiation exposure and defining its current magnitude in electrophysiology compared with the other sources of radiation, this position paper wants to offer some very practical advice on how to reduce exposure to patients and staff. The text describes how customization of the X-ray system, workflow adaptations, and shielding measures can be implemented in the cath lab. The potential and the pitfalls of different non-fluoroscopic guiding technologies are discussed. Finally, we suggest further improvements that can be implemented by both the physicians and the industry in the future. We are confident that these suggestions are able to reduce patient and operator exposure by more than an order of magnitude, and therefore think that these recommendations are worth reading and implementing by any electrophysiological operator in the field.

The prognostic value of Doppler echocardiographic-derived coronary flow reserve is not affected by concomitant antiischemic therapy at the time of testing.

BACKGROUND: When wall motion abnormality is the diagnostic end point, concomitant antiischemic therapy heavily modulates the prognostic value of dipyridamole echocardiography test (DET). A negative test result is less benign, and a positive test result is more malignant if performed under therapy. Recently, coronary flow reserve (CFR) was added to wall motion in dual imaging DET. The aim of the study was to determine whether antianginal medications affect the prognostic value of Doppler echocardiographic-derived CFR in patients with known or suspected coronary artery disease undergoing DET. METHODS: In a prospective, multicenter, observational study, we evaluated 1,779 patients (1,072 males; 64 +/- 11 years) who underwent high-dose dipyridamole (0.84 mg/kg for 6 minutes) stress echo with CFR evaluation of left anterior descending (LAD) artery by Doppler. RESULTS: Seven hundred thirty-three (41%) patients were on antiischemic therapy at time of testing (nitrates and/or calcium antagonists and/or beta-blockers). Mean CFR was 2.3. +/- 0.6. At individual patient analysis, 1,141 patients had normal (CFR >2.0) and 638 had abnormal (CFR

The beneficial effect of insulin, glucose, and dipyridamole on regional left ventricular function early after acute myocardial infarction.

BACKGROUND: High-dose glucose-insulin-potassium (GIK) solution has beneficial effects on reducing mortality in acute myocardial infarction. Dipyridamole (DIP) is a powerful antioxidant and increases adenosine concentration. Experimentally, GIK and DIP have additive protective effects in ischemia-reperfusion injury. AIM: This work aims to assess the acute effects of DIP alone, GIK alone, and GIK+DIP on left ventricular function in patients evaluated early after an acute myocardial infarction. METHODS: Ten male patients (age 63+/-11 years) with uncomplicated acute myocardial infarction were evaluated within 3 days after admission. All had been treated with systemic thrombolysis and were on full therapy (including beta-blockers) at the time of testing. They underwent stress echocardiography [2D echo, with wall motion score index (WMSI) evaluated in a 16-segment model of the left ventricle, with each segment scored from 1=normal to 4=dyskinetic] during low-dose DIP alone (0.28 mg/kg in 4 min); GIK alone (4-h infusion of glucose 30%, 25 insulin units, and 40 mEq of KCl, at an infusion rate of 1.5 ml/kg/h); and GIK+DIP. RESULTS: Regional systolic function (baseline WMSI=1.69+/-0.2) improved after DIP (1.54+/-0.1), GIK (1.54+/-0.1), and, to a greater extent, after GIK+DIP (1.33+/-0.2; p<0.001 vs. baseline; p<0.05 vs. DIP; p<0.05 vs. GIK). CONCLUSION: High-dose GIK has an acute beneficial effect on regional left ventricular function in patients with acute myocardial infarction. This beneficial effect is potentiated by low-dose DIP coadministration.

Lack of prognostic value of normalized integrated backscatter analysis of myocardium in patients with thalassemia major: a long-term follow-up study.

BACKGROUND: Patients with beta-thalassemia major often present with severe anemia and must undergo continuous transfusion therapy, consequently developing iron overload leading to hemochromatosis. Because of these the iron deposits and/or secondary structural changes, patients develop an increase in myocardial integrated backscatter (IB). AIM: To investigate the prognostic value of analyzing acoustic quantitative properties of the myocardium in patients with beta-thalassemia major. PATIENTS AND METHODS: Between 1989 and 1990, 38 patients (mean age: 18 years, range: 7-26, 21 males) with beta-thalassemia major and without clinical signs of cardiac failure were enrolled prospectively. All patients were on chelation therapy (desferroxiamine). To obtain quantitative operator-independent measurement of the IB signal of the left ventricular septum and posterior wall, the ultrasonic radiofrequency signal integrated values were normalized to the pericardial interface and expressed in percentage (IB%). RESULTS: Follow-up was 122 +/- 36 months, during which 15 events (7 cardiac deaths and 8 heart failures) occurred. The event-free survival was comparable in patients with normal and abnormal IB%. Septal IB% was 33 +/- 14 in the 15 patients with events, and 33 +/- 12 in the 25 patients without events (P = ns). The %IB had no prognostic value in this population. A prognostic value was found in multivariate analysis for patient refusal/noncompliance of chelation therapy (P = 0.02, OR: 4.37, 95% CI: 1.72-16.9) and also body mass index (P = 0.04, OR: 1.2, 95% CI: 1.0-1.4). CONCLUSION: Analysis of end-diastolic IB% of myocardium in patients with beta-thalassemia and iron overload was not predictive of adverse cardiac events during long-term follow-up in this study.

Hypnotic modulation of flow-mediated endothelial response to mental stress.

Post-ischaemic flow mediated dilation of peripheral arteries (FMD) is transiently reduced during mental stress. This experiment was aimed at assessing whether hypnosis, which is a powerful relaxation technique, modulated the FMD response to mental stress in subjects with different hypnotic susceptibility. Results showed that hypnotic relaxation prevented the expected stress-related reduction of FMD only in highly hypnotizable subjects, suggesting a protective role of hypnotisability against vascular damage.

Does hypnotizability modulate the stress-related endothelial dysfunction?

Previous studies suggest that hypnotizability represents a protective factor against the cardiac effects of cognitive stress and that hypnosis prevents vascular stress-induced modifications in highly hypnotizable individuals. The aim of the experiment was to investigate whether a similar effect at vascular level is present in awake subjects with a high (Highs) and a low (Lows) hypnotic susceptibility. Thus, brachial artery post-ischaemic flow-mediated vascular dilation (FMD) was evaluated non-invasively by ultrasound methodology during cognitive stress (mental computation) in Highs and Lows. Results showed that Highs, similarly to that previously observed in hypnotized Highs and in contrast with Lows, did not exhibit any stress-related endothelial dysfunction (FMD decrement). Thus, hypnotizability should be considered a protective factor against vascular disease.

Prognostic value of pharmacological stress echocardiography is affected by concomitant antiischemic therapy at the time of testing.

BACKGROUND: The aim of this study was to determine whether antianginal medications affect the prognostic value of pharmacological stress echocardiography. METHODS AND RESULTS: From the EPIC-EDIC Data Bank, 7333 patients (5452 men; age; 59+/-10 years) underwent pharmacological stress echocardiography with either high-dose dipyridamole (0.84 mg/kg over 10 minutes; n=4984) or high-dose dobutamine (up to 40 microg x kg(-1) x min(-1); n=2349) (DET) for diagnostic purposes. At the time of testing, 1791 patients were on antiischemic therapy (nitrates and/or calcium antagonists and/or beta-blockers). Patients were followed up for a mean of 2.6 years (range, 1 to 206 months). DET was positive for myocardial ischemia in 2854 patients (39%) and negative in 4479 (61%). Total mortality was 336 (4.5%). Death was attributed to cardiac causes in 161 patients (2.1%). Survival was highest in patients with negative DET off therapy and lowest in patients with positive DET studied on therapy (95% versus 81%; P=0.0000). Survival was comparable in patients with a negative test on therapy and in patients with a positive test off therapy (88% versus 84%, P=NS). CONCLUSIONS: Ongoing antiischemic therapy at the time of testing heavily modulates the prognostic value of pharmacological stress echo. In the presence of concomitant antiischemic therapy, a positive test is more prognostically malignant, and a negative test less prognostically benign.

Traditional acupuncture does not modulate the endothelial dysfunction induced by mental stress.

Acupuncture is a useful tool to treat many diseases, including cardiovascular disorders, but its modulation of stress-related responses is still debated. Aim of this study was to estimate whether the traditional Chinese acupuncture affected the transient impairment of the brachial artery flow-mediated dilation (FMD) produced by acute mental stress. In addition, since a high susceptibility to hypnosis attenuates the endothelial dysfunction elicited by mental calculation, the possible interaction between acupuncture and hypnotizability was investigated. Five low-to-medium and five medium-to-high hypnotizable healthy subjects joined two experimental sessions, for real and sham acupuncture. FMD and heart rate were measured in three conditions: baseline (PRE), after the real or sham acupuncture (ACU) and after mental calculation (MS). Needles were inserted into specific acupoints for real acupuncture and into non-acupoints, corresponding to the same spinal segment, for sham acupuncture. Results showed that the stress-related endothelial dysfunction was not modulated by acupuncture, but influenced by hypnotizability. In fact, highly hypnotizable subjects did not present any dysfunction, at variance with non-susceptible individuals that exhibited the expected stress-related FMD reduction (Mean +/- SD; PRE, 12.10 +/- 2.59; ACU, 10.73 +/- 3.45; MS, 6.48 +/- 1.72). Thus, hypnotizability appears more effective than acupuncture in contrasting the stress effects on the endothelial function. In conclusion, our study indicates the importance of patients' psychological evaluation in order to choose proper relaxation techniques and to evaluate therapeutic results and the necessity to integrate the alternative medicine practice with scientific research.