Impact of stent implantation on endothelial shear stress.

BACKGROUND: Endothelial shear stress (ESS) may play a key role in the pathobiology of stent restenosis (SR). Nevertheless, limited data are available about ESS and its relation to SR. PATIENTS AND METHODS: We enrolled 14 patients who underwent successful percutaneous coronary intervention (PCI) in this study. Three-dimensional (3D) reconstruction of 14 coronary arteries before and after stent implantation was performed. Using computational fluid dynamics, mean ESS was calculated proximally, in tertiles within and distal to the stent, both before and after stent implantation. RESULTS: Stent implantation resulted in a significant ESS decrease in the entire atherosclerotic lesion (1.83 vs. 1.26 Pa, p = 0.02). Regarding the five territories in which the entire lesion was divided, ESS decrease was marginally significant in the area of the second in-stent tertile, and in the area 5 mm distal to the stent, whereas ESS decrease was not significant in the area 5 mm proximal to the stent, and in the area of the first and third in-stent tertile. At 12 months, two patients had SR, but restenosis was not related to ESS decrease. CONCLUSION: ESS decreases after stent implantation but not uniformly, with the major reduction being in the middle tertile of the stent, and distal to the stent. In-stent ESS decrease may create local hemodynamic conditions leading to in-stent and in-segment restenosis.

Epidemiological characteristics, management and early outcomes of acute coronary syndromes in Greece: The PHAETHON study.

INTRODUCTION: In view of recent therapeutic breakthroughs in acute coronary syndromes (ACS) and essential demographic and socioeconomic changes in Greece, we conducted the prospective, multi-center, nationwide PHAETHON study (An Epidemiological Cohort Study of Acute Coronary Syndromes in the Greek Population) that aimed to recruit a representative cohort of ACS patients and examine current management practices and patient prognosis. METHODS: The PHAETHON study was conducted from May 2012 to February 2014. We enrolled 800 consecutive ACS patients from 37 hospitals with a proportional representation of all types of hospitals and geographical areas. Patients were followed for a median period of 189 days. Outcome was assessed with a composite endpoint of death, myocardial infarction, stroke, urgent revascularization and urgent hospitalization for cardiovascular causes. RESULTS: The mean age of patients was 62.7 years (78% males). The majority of patients (n=411, 51%) presented with ST-elevation myocardial infarction (STEMI), whereas 389 patients presented with NSTEMI (n=303, 38%) or UA (n=86, 11%). Overall, 58.8% of the patients had hypertension, 26.5% were diabetic, 52.5% had dyslipidemia, 71.1% had a smoking history (current or past), 25.8% had a family history of coronary artery disease (CAD) and 24.1% had a prior history of CAD. In STEMI patients, 44.5% of patients were treated with thrombolysis, 38.9% underwent a coronary angiogram (34.1% were treated with primary percutaneous coronary intervention) and 16.5% did not receive urgent treatment. The pain-to-door time was 169 minutes. During hospitalization, 301 (38%) patients presented one or more complications, and 13 died (1.6%). During follow-up, 99 (12.6%) patients experienced the composite endpoint, and 21 died (2.7%). CONCLUSIONS: The PHAETHON study provided valuable insights into the epidemiology, management and outcome of ACS patients in Greece. Management of ACS resembles the management observed in other European countries. However, several issues still to be addressed by public authorities for the timely and proper management of ACS.

Embolization after percutaneous coronary intervention in acute coronary syndrome. Saphenous vein grafts versus native coronary arteries.

AIMS: The aim of this study was to assess the occurrence of distal embolization and to quantify the amount of embolic material captured during stent implantation in native coronary arteries, as compared with saphenous vein grafts (SVG) in patients at different time periods after an acute coronary syndrome. PATIENTS AND METHODS: In all, 104 patients presenting with unstable or stable angina underwent percutaneous coronary intervention (PCI) in 107 vessels and stent implantation in 112 lesions, 53 % of which were in SVG. RESULTS: Device deployment and retrieval was successful in 111 lesions. Embolic material was detected in 74 % of the protection devices. Early PCI, during a 2-week period after the last ischemic episode, was associated with larger embolic load, especially in the right coronary artery. The length of the lesion was the only preprocedural independent variable that was found to be a significant predictor for the presence of emboli (p = 0.002). The stent diameter and the maximum dilatation pressure were the two procedural variables found to be significant predictors for the presence of emboli (p = 0.025 and p = 0.008, respectively). The irregularity of the lesion and the number of stents deployed were found to have a predictive correlation to the total area of the embolic particles (p = 0.04 and p = 0.005, respectively). CONCLUSION: Distal embolization of atherosclerotic debris is a frequent phenomenon after PCI not only in SVG but also in native vessels. The amount of embolic material seems to be related to the atherosclerotic burden of the vessel and to the early timing of the procedure as related to acute coronary syndrome.

Pheochromocytoma crisis presenting with cardiogenic shock.

Pheochromocytoma is a catecholamine-secreting tumor of the adrenal glands whose typical presentation includes the triad of headache, palpitations, and diaphoresis. Pheochromocytoma crisis is an urgent medical condition whose diagnosis and management constitute a challenge for physicians. We present the case of a 55-year-old man who developed cardiogenic shock in the setting of a pheochromocytoma crisis. After stabilizing blood pressure with combined administration of α- and ß-blockers, the tumor was surgically removed. Our diagnostic and therapeutic challenges are discussed.

Hypertrophic cardiomyopathy associated with an anomalous origin of right coronary artery. Case report and review of the literature.

We present a case of patient with hypertrophic cardiomyopathy and an anomalous right coronary artery with left main artery origin and an interarterial course. The coexistence of these two different entities is extremely rare but of major clinical significance because both are associated with an increased risk of sudden cardiac death. In addition, a review of the literature comprising 14 other cases with this combination is provided.

Cholesterol embolization syndrome following thrombolysis during acute myocardial infarction.

BACKGROUND: Cholesterol embolization syndrome (CES) is the result of atherosclerotic plaque erosion and subsequent dislodgement of cholesterol crystals from the core of the plaque to the peripheral arteries. The source of emboli is usually located in the aorta, whereas the most commonly affected organs are the skin and the kidneys. CASE REPORT: The case of a 69-year-old male with cyanotic painful discoloration of his toes following thrombolysis for acute myocardial infarction 1 month previously is presented. Both transesophageal echocardiography and magnetic resonance aortography showed a diffuse ulcerated atherosclerotic plaque in the course of descending thoracic aorta, while a skin biopsy of the cyanotic toes revealed cholesterol crystals in the lumen of the small diameter arteries. CONCLUSION: Cholesterol embolizations from the aorta are difficult to treat and may end in renal failure. Since treatment options are limited without proven efficacy, increased awareness by the clinicians is needed.

The factors contributing to the risk of sudden infant death syndrome.

Sudden infant death syndrome (SIDS) is defined as the sudden death of an infant under one year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene and review of the clinical history. SIDS is one of the leading causes of infant mortality and occurs from the first month, until the first year of life for newborns and infants.The aim of this review was to identify and examine risk factors responsible for causing the sudden infant death and to propose certain measures in order to protect newborns and infants from sudden death. The potential factors that contribute to the occurrence of SIDS include inadequate prenatal care, low birth weight (<2499gr), premature infants, intrauterine growth delay, short interval between pregnancies and maternal substance use (tobacco, alcohol, opiates). Moreover, factors related to infant's sleep environment such as the prone or side sleeping position and thick coverlet increase the risk of sudden death in infants. Also, the combination of risk factors such as that of prone sleeping position and soft bed mattress are linked to a 20-fold increased risk of death. Finally, polymorphisms in the serotonin transporter gene (5-HTT), viral respiratory infections, long Q-T (responsible for the presence of fatal arrhythmia) are related to the SIDS.Literature review indicates that each individual risk factor contributes to the appearance of SIDS and the establishment of certain protective measures for parents and health professionals has reduced its prevalence. But the precise identification of the SIDS causes and how these contribute to the occurrence of sudden death in neonates and infants, remains a challenge for health professionals.

Clinical applications of intravascular ultrasound (IVUS): experience from an academic high volume centre of Northern Greece.

BACKGROUND: Intravascular ultrasound (IVUS) has become a valuable tool adjunctive to coronary angiography due to its ability to directly image atheroma and the vessel wall. We aimed to evaluate the use of IVUS during diagnostic angiography and coronary interventions in a coronary intervention academic high volume center of northern Greece. PATIENTS AND METHODS: IVUS studies have been retrospectively retrieved from 2005 to 2008 from the archives of the catheterization laboratory of our department. IVUS was performed in 403 patients (294 male) of mean age 62±6 years. Indications for coronary angiography +/- intervention were acute coronary syndromes (49%), stable angina (46%) and previous coronary angioplasty evaluation (5%). RESULTS: Forty eight per cent of the IVUS studies were performed in left anterior descending artery (LAD), 25% in right coronary artery (RCA), 18% in left circumflex artery (LCx), and the rest (9%) in left main coronary artery (LMCA) or in coronary branches. Indications for performing an IVUS study were assessment of intermediate lesions (60%), evaluation of stent placement (36.5%), and determination of stent restenosis aetiology (3.5%). Among studies performed for assessment of intermediate lesions, 63% showed a non critical stenosis. IVUS after coronary stenting revealed a suboptimal stent placement in 77% of the cases, while in cases of stent restenosis, IVUS showed inadequate initial stent deployment in 43% of the patients. CONCLUSIONS: The use of IVUS in our department has contributed to the optimization of intervertional treatment of coronary lesions by means of evaluating borderline lesions, stenting placement and stent restenosis.

Brugada syndrome associated with supraventricular tachycardia: diagnostic and therapeutic strategies.

We report the case of a patient with Brugada syndrome and a history of palpitations who presented with an episode of syncope and developed supraventricular tachycardia in the electrophysiological study. The patient was treated with radiofrequency ablation for the supraventricular tachycardia and an implantable cardioverter defibrillator for the Brugada syndrome. At 18 months following implantation of the defibrillator an electrical storm with ventricular fibrillation episodes occurred followed by appropriate discharges of the defibrillator.

Left ventricular function in elite rowers in relation to training-induced structural myocardial adaptation.

To examine left ventricular (LV) function in elite young athletes in relation to structural adaptation to prolonged intense training. Conventional echocardiography and tissue Doppler imaging (TDI) were performed in 15 elite rowers and 12 sedentary matched controls. Rowers had increased LV mass index, septal (12 vs 10 mm, P<0.005) and posterior wall thicknesses (12 vs 9 mm, P<0.001) and increased relative wall thickness. Septal and lateral systolic velocities were enhanced in rowers (septal S(m)=8.5 vs 6.3 cm/s, P<0.001; lateral S(m)=11.4 vs 8.0 cm/s, P<0.005), representing a 35% and 42% increase, respectively. Similarly, septal and lateral early diastolic velocities were enhanced (septal E(m)=12.1 vs 9.5 cm/s, P<0.01; lateral E(m)=16.6 vs 11.6 cm/s, P<0.001), representing a 27% and 43% increase, respectively. Systolic and early diastolic TDI velocities of the lateral wall showed a positive correlation (r=0.65, P<0.01) in athletes indicating a parallel improvement of systolic and diastolic function, while LV stiffness was decreased [(E/E(m))/(LV end-diastolic diameter)=1.13 vs 1.57, P<0.005). Both systolic and diastolic LV function were improved in elite rowers, despite a pattern of concentric hypertrophy.

Arrhythmias, sudden cardiac death and incapacitation of pilots.

Inflight medical emergencies occur at a rate of 20 to 100 per million passengers, with a death rate of 0.1 to 1 per million. Cardiac, neurologic, and respiratory complaints comprise the more serious emergencies, as defined by aircraft diversion or use of ground-based medical assistance. In this paper, we review changes seen in the resting electrocardiogram in normal individuals exposed to high altitude, alongside important implications for patients with heart diseases in high altitude exposures and the possible effects of high altitude to permanent cardiac pacemakers. Arrhythmias in pilots and public safety are revisited together with the guidelines of the Joint Aviation Requirements (JAR) in Europe. The situation of Military flights is also discussed. Physicians ought to become knowledgeable about the specific medical job standards for their patients when asked to render opinions regarding fitness to fly. A database must be established to obtain prospective data that defines the risk of accidents in patients who are or were being treated for arrhythmias. Current guidelines could then be updated and revised as appropriate.

Doppler echocardiographic evaluation of right ventricular diastolic function in hypertrophic cardiomyopathy.

AIMS: Left ventricular diastolic function in patients with hypertrophic cardiomyopathy has been adequately studied. In contrast there are few studies concerning right ventricular diastolic function in hypertrophic cardiomyopathy. We studied right ventricular diastolic function in patients with hypertrophic cardiomyopathy using Doppler echocardiography. METHODS AND RESULTS: We studied 20 patients with hypertrophic cardiomyopathy (mean age 43.6+/-13.8 years) and 20 healthy volunteers (control group, mean age 43+/-13.8 years). We calculated left ventricular and right ventricular diastolic indices using pulsed Doppler echocardiography. Hypertrophic cardiomyopathy patients compared with controls had significantly lower right ventricular-E/A ratio (1.01+/-0.40 vs 1.30+/-0.28, P<0.04), significantly prolonged right ventricular isovolumic relaxation time (170+/-72 vs 32+/-23 ms, P<0.001), and also significantly prolonged right ventricular deceleration time (160+/-58 vs 118+/-35 ms, P<0.01). There was also strong significant correlation between right ventricular deceleration time and left ventricular deceleration time (r=0.78), right ventricular-E/A ratio and left atrial filling fraction (r=-0.55) and between right atrial filling fraction and left atrial filling fraction (r=0.75). CONCLUSIONS: Right ventricular diastolic function in patients with hypertrophic cardiomyopathy is impaired, reflecting abnormal relaxation. Right ventricular diastolic indices correlate well with those of left ventricle.

Doppler echocardiographic evaluation of right ventricular diastolic function in isolated valvular aortic stenosis.

BACKGROUND AND AIM OF THE STUDY: Left ventricular diastolic function (LVDF) in patients with aortic stenosis (AS) has been adequately studied, in contrast to right ventricular diastolic function (RVDF). In this study, RVDF in patients with AS was evaluated using pulsed-wave Doppler echocardiography. METHODS: The study population comprised 20 patients with isolated AS (mean age 53.7 +/- 6.5 years) and 20 healthy volunteers (control group, mean age 52.6 +/- 8.8 years). The diastolic indices of right ventricular (RV) function were calculated using transtricuspid and transpulmonary Doppler flow velocities. Statistical analysis was performed using Student's t-test. There was no statistically significant difference between patients and controls with regard to age, height, bodyweight, heart rate, systolic and diastolic blood pressures, end-diastolic and end-systolic left ventricular (LV) diameter, LV fractional shortening and RV end-diastolic diameter. RESULTS: RV diastolic indices in patients (versus controls) were as follows: E/A ratio of transtricuspid flow waves was significantly lower (0.88 +/- 0.20 versus 1.25 +/- 0.33, p < 0.001); deceleration time of E wave was significantly longer (184 +/- 3 versus 127 +/- 3 ms, p < 0.001); atrial filling fraction was significantly augmented (43.1 +/- 7.7 versus 33.6 +/- 7.6%, p < 0.001); and isovolumic relaxation time was significantly prolonged (116 +/- 73 versus 31 +/- 15 ms, p < 0.001). There was no statistically significant correlation between diastolic indices and interventricular septum thickness and LV mass index. CONCLUSIONS: RVDF in AS patients is impaired, reflecting abnormal relaxation.

Intravenous administration of diltiazem in the treatment of supraventricular tachyarrhythmias.

UNLABELLED: The aim of the study was to investigate the efficacy of diltiazem bolus intravenous administration, compared to disopyramide, in the treatment of various types of paroxysmal supraventricular tachyarrhythmias. METHOD: Fifty patients (23 males, 27 females, mean age 47.7 +/- 15.2 years) with paroxysmal supraventricular tachyarrhythmia (20 with paroxysmal atrial tachycardia, 23 with paroxysmal atrial fibrillation and rapid ventricular response and 7 with atrial fluttering) were studied. Diltiazem at a dose of 0.25-0.30 mg/kg BW or disopyramide at a dose of 50 mg were given bolus IV. If conversion of the arrhythmia to sinus rhythm could not be achieved with the initial drug, the alternate was given. The order of administration of the drugs was random, independent of the type of the arrhythmia. Before and during drug administration detailed clinical examination and frequent blood pressure (BP) measurements were performed. Twenty-four hour Holter monitoring was done in all patients, starting with the administration of the antiarrhythmic drug. RESULTS: 1) Paroxysmal atrial tachycardia: diltiazem administration converted the arrhythmia to sinus rhythm in all patients while disopyramide in only 1 of 9 patients who received this drug. 2) Paroxysmal atrial fibrillation: disopyramide converted the arrhythmia in 5 patients without significant change in ventricular response in the others. Diltiazem did not convert the arrhythmia though it caused significant decrease in ventricular response (< 100 bpm) and in 1 patient an important bradycardia (45 bpm). 3) Atrial fluttering: disopyramide converted the arrhythmia to sinus rhythm in 1 patient without significant change in the ventricular response in the others. Diltiazem caused significant decrease in the ventricular response without conversion to sinus rhythm. During conversion to sinus rhythm an AV junctional rhythm of short duration (< 1 min) was noticed in 5 patients and a short pause (< 2 sec) with or without an initial premature contraction in the remaining 21. Disopyramide administration was not associated with side effects. Diltiazem administration cause small (< 20 mm Hg), transient (< 30 min) decrease of BP without symptoms with the exception of the patient with bradycardia in whom the BP decrease was significant (90/60 from 160/80 mm Hg) followed by intense symptoms which lasted for six hours. CONCLUSIONS: Diltiazem administration is extremely effective in conversion of paroxysmal atrial tachycardia to sinus rhythm. In addition it retards ventricular response in patients with atrial fibrillation and fluttering. Compared to disopyramide these effects of diltiazem are more pronounced and clinically pertinent.

The diagnostic value of the determination of troponin T in the diagnosis of unstable angina.

UNLABELLED: The purpose of the study is the predictive value of determination of Tr-T in diagnosis of unstable angina. METHODS: 35 pts (24 male, 11 female, mean age 53.4 +/- 5 years) were studied. Group A: 20 pts (15 male, 5 female, mean age 50 +/- 6 years) with unstable angina. Group B: 15 pts (9 male, 6 female, mean age 56.4 +/- 4 years) with stable angina RESULTS: pts with stable angina (group B) had normal value of CPK-MB, SGOT, LDH, Tr-T. Eight pts with unstable angina (group A) had increased value of Tr-T with normal value of CPK-MB, SGOT, LDH. In conclusion the determination of Tr-T is helpful in diagnosis of unstable angina and it may be useful in the prognosis of these pts.