Objectives: Prehypertension is a predictor for the future development of hypertension and represents an increased risk for cardiovascular morbidity and mortality. Prolonged intra/interatrial conduction times demonstrated by P wave dispersion (PD) and tissue Doppler echocardiography (TDE) are related to the development of atrial fibrillation. The aim of this study was to evaluate atrial conduction time by PD and TDE in patients with prehypertension.
Study design: In 46 prehypertensive patients (22 males, 24 females; mean age 56.5±12.3 years) and 39 normotensive healthy controls (19 males, 20 females; mean age 55.8±11.7 years), we measured P wave duration and dispersion on 12-lead electrocardiography, and atrial electromechanical coupling intervals (PA) by TDE.
Results: Maximum P wave duration (Pmax) and PD were prolonged in prehypertensives compared to controls (Pmax 110.1±13.8 vs. 91.4±7.7 msec, p<0.001; PD 55.7±11.1 vs. 36.8±5.7 msec, p<0.001). Atrial PAs measured at the lateral and septal mitral annuluses were significantly delayed in the prehypertensive group (lateral PA 76.5±10.1 vs. 65.4±10.4 msec, p<0.001; septal PA 59.0±6.4 vs. 53.5±7.5 msec, p=0.002). Both interatrial (lateral PA-tricuspid PA) and intra-atrial (septal PA-tricuspid PA) conduction times were delayed in the prehypertensive group (25.8±9.3 vs. 17.0±9.5 msec, p<0.001; 9.2±3.7 vs. 6.7±3.0 msec, p=0.008, respectively). Correlation analysis showed that both Pmax and PD were correlated with interatrial (r=0.38, p<0.001 and r=0.40, p<0.001, respectively) and intra-atrial (r=0.31, p=0.01 and r=0.38, p<0.001, respectively) electromechanical delays.
Conclusion: Our finding of significant prolongation of atrial electromechanical coupling and PD may indicate an increased risk for the development of atrial fibrillation in prehypertensive subjects.

Objectives: We evaluated the efficacy and outcome of primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) due to saphenous vein graft (SVG) occlusion.
Study design: We reviewed 2,646 consecutive patients (mean age 56.6±11.8 years) who underwent primary PCI for STEMI between 2003 and 2009. All clinical and angiographic data and in-hospital and long-term (median 22 months) outcomes were retrospectively collected. The patients were classified into two groups based on the lesions treated with primary PCI, i.e., native vessels (n=2,625) and SVG (n=21).
Results: Compared to patients with occluded native vessels, patients with SVG occlusion had significantly higher rates of coronary bypass operation (100% vs. 2.3%, p<0.001), previous myocardial infarction (52.4% vs. 10.8%, p<0.001), and diabetes mellitus (52.4% vs. 25.1%, p=0.002), but lower frequency of anterior myocardial infarction (9.5% vs. 49.3%, p<0.001). Tirofiban use (71.4% vs. 48.2%, p=0.01) and three-vessel disease (81% vs. 25.6%, p<0.001) were significantly more common in the SVG group. The rate of successful primary PCI was lower in SVG occlusions compared to native vessels (61.9% vs. 84.7%, p=0.01). The two groups did not differ significantly with respect to in-hospital and long-term cardiovascular events and mortality (p>0.05). In multivariate logistic regression analysis, application of PCI to SVG was found to be an independent predictor for unsuccessful procedure (OR 6.76, 95% CI 2.05-22.21; p=0.002).
Conclusion: Although the success rate of primary PCI in SVG lesions was lower compared to native vessels, this did not have an adverse effect on postprocedural cardiovascular events and mortality in patients presenting with STEMI.

Objectives: We evaluated the effects of thyroid hormone levels and interleukin-8 levels on prognosis in patients undergoing congenital heart surgery under cardiopulmonary bypass (CPB).
Study design: The study included 41 consecutive children (19 boys, 22 girls; mean age 3.4±3.1 years; range 0.3 to 12 years). The patients were divided into two groups based on the presence or absence of postoperative low cardiac output state (LCOS). The definition of LCOS included oliguria, tachycardia, metabolic acidosis, and increased plasma lactate level. Plasma total (tT4) and free (fT4) thyroxine, total (tT3) and free (fT3) triiodothyronine, thyroid stimulating hormone (TSH), and interleukin-8 (IL-8) levels were measured preoperatively and at 48 hours postoperatively.
Results: Postoperatively, nine patients (22%) developed LCOS. While the two groups were similar with respect to preoperative levels of thyroid hormones, lactate, and IL-8, postoperative tT3 and fT3 levels were significantly lower, and lactate and IL-8 levels were significantly higher in the LCOS group (p<0.05). In correlation analysis, postoperative IL-8 level showed significant correlations with CPB time (r=0.66), duration of mechanical ventilation (r=0.68), and inotropic requirement (r=0.59) (for all p<0.001). On the other hand, LCOS was significantly correlated with the following: preoperative tT4 (r=-0.32, p=0.043) and postoperative fT3 (r=-0.44, p=0.004) levels, duration of mechanical ventilation (r=0.56, p<0.001), intensive care unit stay (r=0.45, p=0.003), and cross-clamp time (r=0.43, p=0.005). Regression analysis showed preoperative level of tT4 as the independent predictor of LCOS (t=-2.092, p=0.045). Mortality occurred in four patients (9.8%) in the early postoperative period, all of whom were in the LCOS group.
Conclusion: Our findings suggest that the development of LCOS after congenital heart surgery is associated with decreased total and free T3, and increased IL-8 levels at 48 hours, and preoperative tT4 level is an independent predictor of LCOS.

Objectives: Lipid levels of most patients receiving antilipidemic therapy are not under control as proposed by the guidelines. We evaluated adherence to statin therapy and LDL cholesterol goal attainment in type 2 diabetic and secondary prevention patients.
Study design: A total of 194 patients (131 men, 63 women; mean age 57±11 years) who had been on statin therapy for at least a year for a target LDL cholesterol level of <100 mg/dl were administered a two-part questionnaire. The first part inquired demographic and clinical characteristics, duration of hyperlipidemia, referral to a dietician, risk factors and, if present, the reasons for drug discontinuation. The second part consisted of 23 questions (total score 30) inquiring the knowledge levels of patients about hypercholesterolemia.
Results: There were 61 primary (31.4%, diabetics) and 133 secondary (68.6%) prevention patients. The mean LDL level was 122.6±28.7 mg/dl. The incidence of attaining target LDL level was only 23.7% (n=46), being lower in diabetics compared to secondary prevention patients (6.6% vs. 31.6, p<0.0001). The mean knowledge score was 18.2±5. When the threshold score was taken as 18 (median), attainment of the target LDL level was significantly higher in patients having a score of ≥18 (32%) compared to those with a lower score (14.9%). There were 77 patients (40%) who sought dietician counseling. Patients with a high school or higher education and those with dietician counseling had higher knowledge scores compared to those with a lower education level and without dietician counseling (p<0.0001). Intermittent drug discontinuation was seen in 109 patients (56.2%), the most common reason being decrease in cholesterol levels to normal (35%).
Conclusion: Target LDL level was achieved in only about 24%. As the knowledge on hypercholesterolemia accrues, the success rate of LDL cholesterol goal attainment increases.

Objectives: Exercise electrocardiography test (EET) has limited sensitivity and specificity. Recently, color M-mode-derived propagation velocity of the descending thoracic aorta (APV) has been shown to be associated with coronary artery disease (CAD). We evaluated the incremental value of APV for better prediction of CAD in EET-positive patients.
Study design: Color M-mode APV was measured in 342 patients undergoing EET for chest pain and an intermediate likelihood of CAD. Coronary angiography was performed in 199 patients having a positive EET.
Results: The mean APV was 44.5±20.8 cm/sec in patients with a positive EET compared to 63.5±19.6 cm/sec in those with a normal test. Significant CAD was detected in 134 patients (67.3%), involving one vessel (n=41), two vessels (n=52), and three vessels (n=41). Patients with CAD had significantly lower APV values compared to patients with normal coronary arteries (33.8±13.2 vs. 66.6±15.6 cm/sec, p<0.001). An APV value of ≤41 cm/sec predicted CAD with 85.1% sensitivity and 93.8% specificity. An APV of >61 cm/sec had 94% specificity for the estimation of normal coronary arteries. A threshold of >41 cm/sec and a threshold of >61 cm/sec would have avoided unnecessary coronary angiography in 30.7% (61/199) and 21.6% (43/199) of patients with a positive EET but high APV values, with negative predictive values of 75.3% and 84.3%, respectively. In correlation analysis, APV was significantly correlated with Duke treadmill score (r=0.587, p<0.001) and the number of coronary vessels involved (r=-0.767, p<0.001), but not with any of the echocardiographic parameters.
Conclusion: Measurement of APV may improve diagnostic value of EET and may be specifically valuable to exclude false positive EET results, leading the physician to other noninvasive tests for further evaluation of CAD probability.

We report on a case of late stent thrombosis after drug-eluting stent placement in a patient with essential thrombocytosis. A 51-year-old male patient with a three-month history of paclitaxel-eluting stent placement to the left anterior descending artery presented with a complaint of severe retrosternal chest pain. A high platelet count (1,063,000/mm3) was detected two months prior to presentation, which was interpreted as essential thrombocytosis. He was on standard dual antiplatelet therapy (aspirin and clopidogrel). The electrocardiogram showed ST-segment elevation in leads V1-V6. Emergent coronary angiography revealed thrombotic total occlusion at the location of the paclitaxel-eluting stent. Balloon angioplasty was performed yielding a satisfactory result and TIMI 3 flow. Following the procedure, there was no chest pain. His platelet count was 388,000/mm3. He was discharged on medical therapy following an uneventful hospital course. Patients with essential thrombocytosis may not be eligible for drug-eluting stent placement.

Duration of dual antiplatelet therapy after drug-eluting stent implantation is still an important issue awaiting a definite answer. A 50-year-old male patient was admitted with acute-onset chest pain and was diagnosed to have acute anterior myocardial infarction due to very late stent thrombosis. He had a 38-month history of two sirolimus-eluting stent implantation in the proximal left anterior descending (LAD) coronary artery. He had been on warfarin along with clopidogrel 75 mg/day until he decided to cease clopidogrel before a minor dental procedure 10 days before. Findings of physical examination and laboratory tests were normal except for an INR value of 4.4. After a loading dose of 300 mg clopidogrel, he was immediately taken to the catheterization laboratory. Angiography of the left system showed total occlusion of the proximal LAD with a thrombus at the level of the proximal stent. He was successfully revascularized without any complication and was discharged free of symptoms.

Accessory mitral papillary muscle originating from the interventricular septum is a rare congenital anomaly. A 20-year-old male patient presented with a complaint of exertional dyspnea. On cardiac examination, a grade 3/4 diastolic murmur was heard over the right upper parasternal area, and the apical pulsations were easily palpable over the precordium. Transthoracic echocardiography showed severe aortic regurgitation, dilatation of the left ventricle, and an accessory papillary muscle with its chordae, extending from the interventricular septum to the anterior mitral leaflet in the left ventricular outflow tract (LVOT). There was no mitral regurgitation. Color Doppler imaging showed turbulence set up by the abnormal mitral attachment and an associated mild pressure gradient of 20 mmHg across the LVOT. At surgery for aortic valve replacement, degenerative changes in the aortic leaflets were noted. The accessory papillary muscle was spared to maintain mitral valve functions and an aortic bileaflet mechanical prosthetic valve was implanted. During eight months of follow-up, he was well without any signs of left ventricular systolic dysfunction and mitral regurgitation, with a functioning prosthetic valve.

Kearns-Sayre syndrome (KSS) is a rare mitochondrial disease in which neuromuscular structures, endocrine glands, and cardiac conduction systems are most commonly involved. An 11-year-old boy was admitted with blurred consciousness, respiratory instability, and bradycardia of two-hour onset. He was immediately intubated. His medical history included growth retardation and myopic refractive defect for six years, therapy for somatomedin C deficiency for 15 months, and bilateral ptosis for three months. On physical examination, he was unconscious, had a peak heart rate of 40/min, blood pressure of 60/20 mmHg, and a weak pulse. Laboratory findings showed elevated blood lactate and blood pyruvate levels and an increased lactate/pyruvate ratio. The electrocardiogram showed complete atrioventricular block and echocardiography showed mitral valve prolapse. Following implantation of a temporary transvenous cardiac pacemaker, his heart rate and clinical condition improved. Further analysis with cranial magnetic resonance (MR) imaging demonstrated hyperintense signal changes in the subcortical white matter of the two cerebral hemispheres, bilateral thalamus, putamen, cerebral peduncles, dorsal medulla, and midbrain. The typical clinical and MR findings confirmed the initial diagnosis of KSS. A permanent cardiac pacemaker was implanted into the right ventricle.

Myocarditis due to H1N1 influenza infection has not been previously described. We report on a case of acute fulminant myocarditis caused by H1N1 influenza A virus infection that mimicked acute coronary syndrome. A 50-year-old man was admitted with dyspnea, fever, cough, vomiting, and atypical chest pain of three-day history. His body temperature, pulse rate, and blood pressure were 39.2 °C, 115 beats/min, and 80/40 mmHg, respectively. Electrocardiography showed sinus tachycardia, 1-mm ST-segment elevation, and absence of R wave progression in anterior leads, and ST depression in anterolateral leads. The chest radiogram revealed diffuse bilateral alveolar infiltrates. Cardiac enzymes were elevated. Despite treatment with aspirin, clopidogrel, low-molecular weight heparin, metoprolol, and an ACE inhibitor, he developed hemodynamic instability on the first day of admission. Echocardiographic examination showed anteroseptal, apical, and lateral wall hypokinesia, left ventricular diastolic dysfunction, and dilatation of all the chambers. There was no abnormal finding on coronary angiography. The diagnosis was considered to be myocarditis; thus, anticoagulant and antiaggregant therapies were discontinued, and empirical broad-spectrum antimicrobial treatment was initiated together with antiviral oseltamivir (2x75 mg/day). The patient’s clinical condition significantly improved. Nasopharyngeal samples were positive for H1N1 influenza A virus. He was discharged on the 15th in good medical condition.

Arterial tortuosity syndrome (ATS) is a rare autosomal recessive connective tissue disease characterized by elongation, tortuosity, aneurysmatic formation, and stenotic lesions in large and medium-size arteries. We present two cases of ATS diagnosed during cardiac examination for murmurs. The first was an 11-year-old boy who had an atypical facial appearance and hyperelasticity. He had a prior operation for inguinal hernia. Echocardiography showed aneurysmatic dilatation in the main pulmonary artery and peripheral stenotic lesions. Angiography and computed tomography angiography confirmed aneurysmatic formation in the main pulmonary artery and multiple stenotic lesions in peripheral arteries and showed elongation and tortuosity of the major branches of the aorta. Surgical reconstruction of the pulmonary arterial system was performed. The second was a 3-month-old girl with an atypical facial appearance, hyperelasticity, and marked hypotonia. The aortic arch could not be visualized during echocardiography. Angiographic examination showed mild bilateral stenosis of distal pulmonary arteries, elongation and tortuosity of the aortic arch and its main branches.

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by increased pulmonary vascular resistance that leads to right ventricular failure. The most common clinical features of PAH are dyspnea and exercise intolerance. Measurement of exercise capacity is of considerable importance for the assessment of disease severity as well as routine monitoring of disease. Maximal, symptom-limited, cardiopulmonary exercise test (CPET) is the gold standard for the evaluation of exercise capacity, whereby functions of several systems involved in exercise can be assessed, including cardiovascular, respiratory, and metabolic systems. However, in order to derive the most useful diagnostic information on physiologic limitations to exercise, CPET requires maximal effort of the patient, which can be difficult and risky for some severely ill patients. Moreover, it requires specific exercise equipment and measurement systems, and experienced and trained personnel. Thus, routine clinical use of CPET to assess exercise capacity in patients with PAH may not always be feasible. A practical and simple alternative to CPET to determine exercise capacity is the 6-minute walk test (6MWT). It is simple to perform, safe, and reproducible. In contrast to CPET, the 6MWT reflects a submaximal level of exertion that is more consistent with the effort required for daily physical activities. This review focuses on the role of CPET and 6MWT in patients with PAH.