Martin Osranek

Increased Left Atrial Volume Index: Potent Biomarker for First-Ever Ischemic Stroke

OBJECTIVE To establish the incidence and correlation of increased left atrial volume index (LAVI) in patients with first-ever ischemic stroke. PARTICIPANTS AND METHODS Using our institutions epidemiological database, we defined a cohort of 432 patients (cases) who underwent transthoracic echocardiography within 60 days of first ischemic stroke between January 1, 1985, and December 31, 1994. Left atrial volume was measured with the biplane area-length method, indexed to body surface area (LAVI, expressed as mL/m(2)). The control group consisted of 416 community residents who underwent transthoracic echocardiography as participants in a stroke risk factor study. Increased LAVI was defined as 28 mL/m(2) or higher. Survival in patients was compared with expected survival among white Minnesotans and was further modeled as a function of age, sex, LAVI, and clinical risk factors. RESULTS Among the included 306 patients, 230 (75%) had increased LAVI (mean+/-SD, 49+/-21 mL/m(2)). Patients with increased LAVI were older than those with normal LAVI (mean+/-SD age, 76+/-11 vs 71+/-13 years; P=.003) and had more cardiovascular risk factors (mean+/-SD number, 1.8+/-0.07 vs 1.3+/-0.89; P<.001). Mean LAVI was higher in cases than in age- and sex-matched controls (P<.001). At 5-year follow-up, cases showed excess mortality compared with age-matched controls (P=.001). After variables were adjusted for age, sex, and clinical risk factors, LAVI was independently associated with mortality. CONCLUSION A useful index for prediction of adverse cardiovascular events, LAVI might also predict first ischemic stroke and subsequent mortality.

Hand-carried ultrasound-guided pericardiocentesis and thoracentesis

To date, ultrasound-guided centeses have required the use of large, diagnostic ultrasound equipment that can be cumbersome and not readily available. In this study, we sought to evaluate the use of portable, hand-carried ultrasound devices in guidance of pericardiocentesis and thoracentesis. Hand-carried ultrasound was used to define location of the maximal extent of the effusion and its proximity to the skin surface, confirm needle entry and site, and to evaluate postprocedural result. A total of 12 patients who were stable and hospitalized were prospectively enrolled, 9 for pericardiocentesis and 3 for thoracentesis. We concluded that under the direction of a suitably trained physician, hand-carried ultrasound provided images suitable for guidance of a pericardiocentesis or thoracentesis preprocedurally, intraprocedurally, and postprocedurally.

Arterioventricular Coupling and Ventricular Efficiency After Antihypertensive Therapy. A Noninvasive Prospective Study

Patients with hypertension exhibit impaired energetic coupling between the ventricle and the arterial system, leading to reduced cardiac mechanic efficiency and exercise capacity. We tested whether blood pressure normalization with current antihypertensive therapy can improve arterioventricular coupling. Eighteen hypertensive patients without other cardiovascular disease were examined before and after antihypertensive therapy. Transthoracic echocardiography was performed. Central aortic pressure waveforms, including end-systolic pressure, were derived from radial artery applanation tonometry. Afterload was increased with isometric handgrip exercise. Central aortic end-systolic pressure and ventricular volumes at rest and handgrip were used to calculate ventricular elastance, effective arterial elastance, arterioventricular coupling (effective arterial elastance/ventricular elastance), and mechanical efficiency. After 142±67 days, systolic blood pressure decreased from 150.9±14.6 to 119.8±9.2 mm Hg (P<0.00001), diastolic blood pressure from 85.9±14.8 to 68.8±8.4 mm Hg (P=0.00002), and cardiac output from 5.8±1.7 to 4.9±1.8 L/min (P=0.03). Resting left ventricular end-systolic volume, ejection fraction, and septal thickness did not change. Ventricular elastance increased from 1.7±1.0 to 3.2±1.4 mm Hg/mL (P=0.00002), whereas effective arterial elastance decreased from 1.4±0.5 to 1.2±0.4 mm Hg/mL (P=0.02). Effective arterial elastance/ventricular elastance decreased in all patients, from 1.1±0.8 to 0.4±0.2 (P=0.0002). Efficiency improved at rest (72.9±5.8% versus 83.5±5.7%; P<0.00001) and during handgrip (63.5±7.8% versus 78.9±7.1%; P<0.00001). In hypertensive patients, optimal brachial and central blood pressure reduction shifts arterioventricular coupling from cardiac output maximization to ventricular mechanical efficiency optimization. This occurs before significant changes in ventricular geometry and may be responsible for early clinical improvements.

Adventitial response to intravascular brachytherapy in a rabbit model of restenosis

ZusammenfassungEinleitungSchwere koronare Ereignisse (MACE) treten spät nach vaskulärer Brachytherapie häufiger auf als bei Kontrollpatienten. Wir untersuchten Veränderungen in der Adventitia nach intravaskulärer Bestrahlung in einem Kaninchenmodell, da expansives Remodeling mit einer schlechten Prognose nach Gefäßinterventionen verbunden ist.MethodikBei zwanzig normolipidämischen Kaninchen wurde eine Ballondilatation in beiden Aa. iliacae externae durchgeführt. In einem Gefäß wurde anschließend randomisiert eine Bestrahlung mit einer 90Y-Quelle (15 Gy oder 30 Gy in 0,5 mm Tiefe in der Gefäßwand) durchgeführt. Nach vier Wochen wurden an den autoptisch entnommenen Gefäßen morphometrische Messungen durchgeführt und die Zelldichte und der Kollagengehalt bestimmt. Mit Ki67 wurden proliferierende, mit TUNEL apoptotische Zellen nachgewiesen. Ein Proliferations-bzw. Apoptoseindex wurde als Anzahl der jeweils positiven Zellen pro Gesamtzellzahl × 100 angegeben.ErgebnisseDie Neointimafläche reduzierte sich auf 0,27±0,3 mm2 nach Bestrahlung gegenüber 0,55±0,2 mm2 bei Kontrollgefäßen (p=0,007), während die Adventitiafläche von 0,62±0,3 mm2 auf 0,87±0,3 mm2 zunahm (p=0,02). Die Bestrahlung verringerte den Proliferations-(0,95±2,6 vs. 3,73±4,7, p=0,026) sowie den Apoptoseindex (0,006±0,02 vs. 0,107±0,2, p=0,03) in der Neointima, aber nicht in den übrigen Gefäßschichten. Der Kollagengehalt und das arterielle Remodeling unterschieden sich nicht zwischen den Gruppen. Hinsichtlich keines Parameters gab es signifikante Unterschiede zwischen der 15 Gy- und der 30 Gy-Gruppe, obwohl die Verdickung der Adventitia in der Hochdosisgruppe ausgeprägter war.SchlussfolgerungIntravaskuläre Betabestrahlung nach Ballonangioplastie bei normolipidämischen Kaninchen ist mit einer Zunahme der Neoadventitia und einer Abnahme der Neointima assoziert. Ein Zusammenhang mit der vermehrten Inzidenz von MACE nach vaskulärer Brachytherapie kann daher angenommen werden.SummaryBackgroundThe incidence of late major adverse cardiac events (MACE) after coronary brachytherapy is higher than in controls. Because expansive remodeling has been shown to correlate with poor clinical outcome after vascular interventions, we studied adventitial changes after intravascular irradiation in a rabbit model.MethodsTwenty normolipidemic rabbits underwent balloon injury in both external iliac arteries. One artery ws assigned for subsequent irradiation with a90Y source (15 Gy or 30 Gy at 0,5 mm in the vessel wall). After four weeks morphometric measurements were made and cell density and collagen amount determined. Staining for Ki67 identified proliferating cells; apoptotic cells were identified by TUNEL staining. Proliferative and apoptotic indices were calculated as the number of respective positive cells/total cell count ×100.ResultsThe neointimal area decreased to 0.27±0.3 mm2 after irradiation compared with 0.55±0.2 mm2 in controls (p=0.007), whereas adventitial area increased from 0.62±0.3 mm2 to 0.87±0.3 mm2 (p=0.02). Irradiation reduced both the proliferative (0.95±2.6 vs. 3.73±4.7, p=0.026) and apoptotic (0.006±0.02 vs. 0.107±0.2, p=0.03) indices in the neointima, but not in the other arterial-wall layers. Collagen amount and arterial remodeling did not differ between the groups. There was no difference between 15 and 30 Gy in any of the parameters, although adventitial thickening was more pronounced in the high-dose group.ConclusionsIn normolipidemic rabbits, intravascular beta-irradiation after balloon angioplasty is associated with an increase in neoadventitia and a reduction of neointima. It is conceivable that this phenomenon may contribute to the increased incidence of late MACE after vascular brachytherapy.

Marked respiratory-related fluctuations in left ventricular outflow tract gradients in hypertrophic obstructive cardiomyopathy: an observational study

Aims Left ventricular outflow (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM) is dynamic and sensitive to many variables that affect left ventricular preload, afterload, and contractility. The haemodynamic effect of normal respiration on LVOT obstruction has not been described. Methods and results We examined 20 patients with HCM who were noted to have phasic respiratory variation of LVOT obstruction on initial transthoracic 2D echocardiogram and Doppler examination. LVOT gradients were re-examined with simultaneous recording of a respirometer. LVOT gradients varied widely during the respiratory cycle; peak gradients were uniformly lowest during inspiration (50.8 mmHg + 25.6) and highest during expiration (90.1 mmHg + 41.8). On average, there was 82.4% ± 39.1 (P ≤ 0.0001) incremental change from inspiration to expiration, in the severity of LVOT obstruction. In 11 patients with mitral annulus inflow, LV inflow (preload) was decreased during inspiration. In 16 patients with isovolumic relaxation time and ejection time measurements, decreased left atrial filling pressure was noted during inspiration, consistent with decreased LVOT obstruction. When compared with a control group of 20 HCM patients who did not have respiratory variation, the study group patients were more overweight (mean body mass index cases 35.1 ± 7.3 vs. control group 29.1 ± 5.1, P = 0.0045) and more likely to have sleep-disordered breathing (n = 15 study group, n = 5 control group). Conclusions Counterintuitive respiratory-related fluctuations in LVOT gradients were observed in this case series of 20 HCM patients. These findings challenge traditional haemodynamic teaching and demonstrate the contribution of LV transmural pressure to LVOT obstruction in certain HCM patients.

Giant Atrial Septal Aneurysm in a 25-Year-Old Woman

A 25-year-old physical fitness trainee was referred to receive an echocardiogram after being told that her ECG was mildly abnormal. She had experienced no symptoms apart from occasional deep, sighing breathing and rare vasovagal spells during adolescence. On physical examination, her second heart sound was somewhat more widely split with inspiration, and a grade 1/6 systolic ejection murmur was heard at the pulmonic region. The echocardiogram showed a huge fenestrated atrial septal aneurysm with …