Implantable loop recorders for assessment of syncope: increased diagnostic yield and less adverse outcomes with the latest generation devices.

AIM: Aim of the study was to compare the diagnostic yield of implantable loop recorders (ILR) of two successive generations for the assessment of syncope. METHODS: Data on patients who had undergone ILR implantation for unexplained syncope in four Italian public hospitals were retrospectively acquired from the Medtronic Clinical Service database. After implantation, routine follow-up examinations were performed every 90 days, while urgent examinations were carried out in the event of syncope recurrence. RESULTS: The following findings were regarded as diagnostic: ECG documentation of a syncope recurrence; documentation of any of the arrhythmias listed by the current guidelines as diagnostic findings even if asymptomatic. Between November 2002 and March 2010, 107 patients received an ILR (40 Medtronic Reveal® Plus; 67 Medtronic Reveal® DX/XT) and underwent at least one follow-up examination. Diagnoses were made in 7 (17.5%) and 24 (35.8%) (P=0.043) patients, with a median time of 228 and 65 days, respectively. Three (42.9%) and 21 (87.5%) (P=0.029) diagnoses were based on automatically detected events, while adverse outcomes occurred in 6 and in 1 (P=0.01) patients, respectively. CONCLUSION: Our results show that the new-generation device offer a higher diagnostic yield, mainly as a result of its improved automatic detection function, and is associated with fewer adverse outcomes.

[Acute myocardial infarction following administration of a synthetic analog of prostaglandin E2 in a subject with an intramural course of the anterior intraventricular artery]. / Infarto miocardico acuto dopo somministrazione di un analogo di sintesi della prostaglandina E2 in soggetto con decorso intramurale dell'arteria interventricolare anteriore.

We report a case of acute myocardial infarction which occurred after administration of a synthetic analog of prostaglandin E2 (PGE2) for the voluntary interruption of pregnancy in a 31-year-old woman who had previously been asymptomatic, with myocardial bridging of the left anterior descending artery. The pathogenesis of the severe ischemia causing myocardial infarction and left ventricle aneurysm is quite unclear. The temporal connection is highly indicative of a causal relationship between the pharmacological effects of a synthetic PGE2 analog and coronary spasm responsible for severe ischemia. The hypothesis of endothelial dysfunction proximal to the intramyocardial artery tract and paradoxical vasoconstriction with platelet activation should be taken into consideration. A possible additional effect seems to be a horizontal coronary steal produced by the administration of PGE2 in the myocardium below the intramyocardial artery tract. It cannot be excluded that pharmacological doses of a synthetic analog of PGE2 may have inverted the vasoactive effects of the substance due to direct stimulation on the delivery of constrictive agonist factors.

Relationship between plasma endothelin-1 levels and myocardial ischemia induced by exercise testing.

At peak exercise, plasma endothelin-1 concentration increases in patients with effort angina as well as thallium-201 radionuclide perfusion defects; the opposite occurs in patients with normal scans and in healthy volunteers. It is concluded that exercise-induced ischemia correlates with enhanced endothelin-1 production.

[Effects of naloxone on plasma levels of atrial natriuretic factor and noradrenaline during water load in moderate heart failure]. / Effetti del naloxone sui livelli plasmatici del fattore natriuretico atriale e della noradrenalina durante carico idrico nello scompenso cardiaco moderato.

BACKGROUND: The aim of our study was to evaluate the effects of endogenous opioids on the secretion of atrial natriuretic factor (ANF) in moderate chronic heart failure (HF). METHODS: We evaluated the effects of i.v. volume load (NaCl 0.9% at 0.25 ml/Kg/min for 60 minutes) on heart rate (HR), on mean arterial pressure (MAP) and on the plasma levels of beta-endorphin (beta-end), met-enkephalin (Met-enk), dynorphin (Dyn), atrial natriuretic factor (ANF) and noradrenaline (NA) in 10 patients (age 58 +/- 9) with HF in NYHA class II (group I) and in 8 healthy control subjects (age 54 +/- 10) group II). The volume load was repeated after at least three days during infusion of naloxone (2 micrograms/Kg/min), evaluating the above mentioned hemodynamic and hormonal parameters. RESULTS: The acute volume expansion caused an increase in ANF concentration (from 51.7 +/- 19.7 to 67.4 +/- 36.9 pg/ml; p < 0.05) and in beta-end (from 11.9 +/- 5.3 to 16.6 +/- 7.5 fmol/ml; p < 0.05), In group I. In group II an isolated increase in ANF was observed (from 14.1 +/- 7.8 to 21.9 +/- 7.9 pg/ml; p < 0.02). No significant changes were detected for HR, MAP, Dyn, Met-enk and NA. In group I the percent increase of ANF is less than in group II (30 vs 55%; p < 0.05). The volume load infused during naloxone infusion caused a significant increase in HR (from 73 +/- 6 to 78 +/- 9 bpm; p < 0.05) and in NA (from 311 +/- 123 to 415 +/- 142 pg/ml; p < 0.05) In group I. In group II, an increase in ANF was detected (from 13.8 +/- 6.0 to 23.6 +/- 5.0 pg/ml; p < 0.01). CONCLUSIONS: Our data suggest that in moderate HF beta-end stimulates the secretion of ANF and inhibits the activity of the sympatho-adrenergic system during acute volume expansion.