Assessment of atrial conduction time in patients with systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus (SLE) is an autoimmune disorder resulting in multisystemic inflammatory damage. Recent articles report that 20% to 30% of deaths in patients with SLE have cardiovascular origin. The aim of this study was to investigate the atrial conduction time in patients with SLE by using high-usefulness tissue Doppler echocardiography (TDI).

METHODS

The study population included 56 patients with SLE (49 women; mean [SD] age, 46.2 [12.2] years, and mean [SD] disease duration, 30.7 [10.9] months) and 45 healthy subjects as control group (39 women; mean [SD] age, 45.8 [12.3] years). P-wave dispersion (PWD) was calculated by using 12-lead electrocardiogram. The timing of atrial contractions (PA) was measured as the interval between the onset of P wave on electrocardiogram and the beginning of A wave on TDI. Atrial electromechanical delay (EMD) was calculated from the lateral (PA lateral), septal (PA septal) mitral annulus, and lateral tricuspid annulus (PA tricuspid).

RESULTS

Lateral mitral annulus and PA septal were significantly longer in the patients with SLE than in the control subjects (66.7 [15.9] vs 56.5 [13.7], P = 0.001, and 53.5 [15.0] vs 45.0 [15.1] milliseconds, P = 0.006, respectively). Interatrial (PA lateral - PA tricuspid) and intra-atrial (PA septal - PA tricuspid) EMD were significantly higher in SLE groups (25.5 [9.7] vs 19.9 [8.3], P = 0.003 and 13.3 [7.7] vs 8.4 [8.0] milliseconds, P = 0.002, respectively). Similarly, maximum P-wave duration and PWD were significantly longer in the patients with SLE than in the control subjects (104.9 [13.5] vs 98.1 [15.1], P = 0.021 and 24.6 [7.4] vs 20.0 [8.1] milliseconds, P = 0.004, respectively). There were significant positive correlations between the disease duration and interatrial EMD (r = 0.611, P < 0.001) and intra-atrial EMD (r = 0.565, P < 0.001). Positive correlation was also present between the disease duration and PWD (r = 0.457, P < 0.001).

CONCLUSION

Atrial EMD is prolonged in patients with SLE. We have also shown that PWD, intra-atrial EMD, and interatrial EMD were significantly correlated with disease duration. This study calls attention to the following: the measurement of atrial conduction time may be clinically helpful in the definition of cardiac involvement.

Early arterial stiffness and inflammatory bio-markers in normotensive polycystic kidney disease patients

BACKGROUND/AIMS

Cardiovascular disease is the main cause of morbidity and mortality in autosomal-dominant polycystic kidney disease (ADPKD) patients. To clarify temporal relationship between ADPKD, hypertension and the loss of renal function, we examined these factors in patients with early-stage ADPKD who did not yet have hypertension.

METHODS

Fifty patients with ADPKD (42% males, 36.6 ± 9.9 years, no blood pressure medication) and 50 healthy controls (44% males, 35.4 ± 6.4 years) were studied cross-sectionally. Pulse wave velocity (PWV), cardiac morphology and function, aortic elastic indexes, estimated glomerular filtration rate (eGFR), 24-hour ambulatory blood pressure, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and highly sensitive C-reactive protein (hs-CRP) were measured in all participants, using conventional methods.

RESULTS

Despite a normal blood pressure, aortic stiffness index and pulse wave velocity values were increased in patients compared to controls (6.8 ± 4.7 vs. 5.1 ± 3.3, p = 0.043 and 9.6 ± 1.3 vs. 5.8 ± 1.1 m/s, p < 0.001). In univariate analysis, IL-6, TNF-α, hs-CRP and eGFR were all significantly correlated with PWV. The independence of these correlations were analyzed in a regression model, and showed PWV to be significantly predicted by IL-6, TNF-α and hs-CRP.

CONCLUSION

Increased arterial stiffness and pulse wave velocity are early manifestations of ADPKD appearing before hypertension or reduced eGFR. However, these vascular abnormalities are related to signs of systemic low grade inflammation, suggesting a common pathophysiological mechanism apparently present also in other vascular diseases but yet to be elucidated.

Coronary ectasia is associated with impaired left ventricular myocardial performance in patients without significant coronary artery stenosis

OBJECTIVES

To determine both ventricular functions and tissue Doppler echocardiography (TDE)-derived myocardial performance index (MPI) in patients with coronary artery ectasia (CAE).

SUBJECTS AND METHODS

Twenty-five patients with CAE (13 men; mean age 57 ± 9 years) and 25 age- and sex-matched controls without CAE (8 men; mean age 54 ± 10 years) were enrolled in the study. Left and right ventricular functions were detected using conventional echocardiography and TDE.

RESULTS

Left ventricle-lateral wall (0.61 ± 0.17; 0.50 ± 0.10, p = 0.02), interventricular septum (0.66 ± 0.17; 0.52 ± 0.10, p = 0.007) and mean MPI (0.63 ± 0.15; 0.51 ± 0.09, p = 0.004) were increased in the CAE group compared to the control group. Right ventricular MPI was similar in both the CAE and control groups (0.58 ± 0.18; 0.52 ± 0.19, p > 0.05).

CONCLUSION

The findings show that left ventricular MPI is different in CAE patients without obstructive coronary artery disease compared to the normal control group. Also in these patients, right ventricular MPI was similar to the control group.

Potential role of plasma myeloperoxidase level in predicting long-term outcome of acute myocardial infarction

We investigated the prognostic importance of plasma myeloperoxidase levels in patients with ST-elevation myocardial infarction (STEMI) at long-term follow-up, and we analyzed the correlations between plasma myeloperoxidase levels and other biochemical values. We evaluated 73 consecutive patients (56 men; mean age, 56 ± 11 yr) diagnosed with acute STEMI and 46 age- and sex-matched healthy control participants. Patients were divided into 2 groups according to the median myeloperoxidase level (Group 1: plasma myeloperoxidase ≤ 68 ng/mL; and Group 2: plasma myeloperoxidase > 68 ng/mL). Patients were monitored for the occurrence of major adverse cardiovascular events (MACE), which were defined as cardiac death; reinfarction; new hospital admission for angina; heart failure; and revascularization procedures. The mean follow-up period was 25 ± 16 months. Plasma myeloperoxidase levels were higher in STEMI patients than in control participants (82 ± 34 vs 20 ± 12 ng/mL; P = 0.001). Composite MACE occurred in 12 patients with high myeloperoxidase levels (33%) and in 4 patients with low myeloperoxidase levels (11%) (P = 0.02). The incidences of nonfatal recurrent myocardial infarction and verified cardiac death were higher in the high-myeloperoxidase group. In multivariate analysis, high plasma myeloperoxidase levels were independent predictors of MACE (odds ratio = 3.843; <95% confidence interval, 1.625-6.563; P = 0.003). High plasma myeloperoxidase levels identify patients with a worse prognosis after acute STEMI at 2-year follow-up. Evaluation of plasma myeloperoxidase levels might be useful in determining patients at high risk of death and MACE who can benefit from further aggressive treatment and closer follow-up.

High Levels of Serum Uric Acid Predict Severity of Coronary Artery Disease in Patients with Acute Coronary Syndrome

We aimed to elucidate the relation between serum uric acid (SUA) level and severity of coronary artery disease (CAD) in nondiabetic, nonhypertensive patients (n = 246) with acute coronary syndrome (ACS). Severity of CAD was assessed by the Gensini score. One, 2, and 3 or more diseased vessels were identified in 87 (35.4%), 55 (22.4%), and 104 (42.2%) patients, respectively. Patients with hyperuricemia had higher Gensini score, high number of diseased vessels, critical lesions, and total occlusion. Serum uric acid level was significantly associated with number of diseased vessels. Serum uric acid was an independent risk factor for multivessel disease by univariate analysis. High levels of SUA associated with the severity of CAD in nondiabetic, nonhypertensive patients with ACS.

Assessment of Red Cell Distribution Width (RDW) in Patients With Coronary Artery Ectasia

Objectives: Coronary artery ectasia (CAE) is characterized by an abnormal dilatation of the coronary arteries. Red cell distribution width (RDW) is a measure of heterogeneity in the size of red blood cell. In this study, we aimed to investigate RDW levels in patients with CAE. Methods: The study population included 54 patients with CAE (28 males; mean age, 59 ± 12) and 40 individuals comprising the control group who had normal coronary arteries (17 males; mean age, 56 ± 10). Admission RDW was measured as part of the automated complete blood count. Results: The RDW was significantly higher in the CAE group than the control ( P < .001). Also, high-sensitive C-reactive protein (hs-CRP) levels in patients with CAE were significantly higher as compared with controls ( P < .001). Conclusion: This study demonstrates that RDW and hs-CRP were higher in the CAE group compared with the control group. These results show that RDW is a reliable, simple, and inexpensive marker for patients with CAE.

Aortic and coronary artery dissection during percutaneous coronary intervention: a case report and review article

Coronary artery dissection is an uncommon but potentially serious complication in percutaneous coronary interventions. We treated a 53-year-old female patient with right coronary spasm, which was misdiagnosed as a coronary lesion. The coronary spasm resolved with nitrate administration, but proximal coronary dissection developed during angiography. It progressed anterograde and led to inferior myocardial infarction and severe hemodynamic instability due to right coronary artery occlusion. Percutaneous intervention failed, and it was determined that coronary dissection progressed retrograde, across the truncus of the aorta. Ascending aortic grafting and coronary bypass surgery were performed. The patient recovered and was discharged after 10 days. Close cardiothoracic observation is mandatory in patient evaluation and management.

Effects of atorvastatin and lisinopril on endothelial dysfunction in patients with Behçet's disease

OBJECTIVE

Behçet's disease is a chronic inflammatory vasculitis. Vascular involvement is one of the major complications of Behçet's disease, during the course of the disease. Previous studies showed that ACE inhibitors and statins may improve endothelial functions in endothelial dysfunction. The aim of our study is to compare the effects of atorvastatin and lisinopril to placebo on endothelial dysfunction in patients with Behçet's disease.

PATIENTS AND METHODS

We prospectively studied 92 (48 female) Behçet's patients who were diagnosed according to the International Study Group criteria. Endothelial dysfunction was evaluated by brachial artery flow-mediated dilatation (FMD) method using high-resolution vascular ultrasound device at baseline and after for 3-month therapy. Patients were consecutively randomized into three groups as (atorvastatin (n = 31), lisinopril (n = 31), and placebo groups (n = 30). Patients in atorvastatin group received 20 mg atorvastatin, lisinopril group received 10 mg lisinopril per day, and placebo group received placebo per day for 3 months.

RESULTS

The baseline characteristics of patients were similar among three groups; however, high-sensitive C-reactive protein (hs-CRP) levels were lower in atorvastatin group than placebo group. A significant improvement in FMD was observed in both atorvastatin (5.0 ± 1.4 vs. 12.8 ± 3.6%, P < 0.001) and lisinopril groups (5.0 ± 1.2 vs. 11.4 ± 5.0%, P < 0.001). Partial significant enhancement was observed in placebo group (4.9 ± 1.1% vs. 5.7 ± 1.0, P = 0.002). However, it was lower than the cutoff value for endothelial dysfunction.

CONCLUSION

These findings suggest that atorvastatin and lisinopril improve endothelial functions in Behçet's disease patients. However, large studies are needed to determine the long-term effects of atorvastatin and lisinopril therapy.

Mad-honey sexual activity and acute inferior myocardial infarctions in a married couple

Mad-honey poisoning can occur after the eating of honey that contains grayanotoxin. Mad honey is intentionally produced from the nectar of Rhododendron ponticum, which grows in Japan, Nepal, Brazil, parts of North America and Europe, and the eastern Black Sea region of Turkey. Low doses of grayanotoxin can cause dizziness, hypotension, and bradycardia, and high doses can cause impaired consciousness, syncope, atrioventricular block, and asystole due to vagal stimulation. Reports of acute coronary syndrome are very rare. Herein, we present the case of a 50-year-old husband and 42-year-old wife who, to improve sexual performance, intentionally ate honey from the Black Sea area of Turkey for 1 week. Within 3 hours of consuming increased amounts of the honey, they presented at our emergency department with acute inferior myocardial infarctions. Coronary angiography revealed normal coronary arteries in both patients. Supportive treatment with atropine rapidly resolved the clinical symptoms and electrocardiographic irregularities. Grayanotoxin-containing rhododendron pollen was detected in the honey.In patients from geographic regions where mad honey can be obtained, mad-honey poisoning should be considered in the differential diagnosis of chest pain, particularly in the presence of unexplained bradyarrhythmia and hypotension. Sexual performance is a chief reason for the purchase of mad honey and self-treatment with it by persons of our patients' ages.

Effect of long-term and high-dose allopurinol therapy on endothelial function in normotensive diabetic patients

OBJECTIVES

Endothelial dysfunction is a well known risk factor for atherosclerosis. Uric acid levels are associated with endothelial dysfunction and atherosclerosis even if in physiological range. Xanthine oxidase inhibition with allopurinol decreases uric acid levels and oxidative stress and improves endothelial function. We have investigated the effect of high-dose and long-term allopurinol therapy on endothelial function in diabetic normotensive patients.

METHODS

This study is a randomized, single-blind, placebo-controlled trial. Both treatment and placebo groups consisted of 50 patients. In the treatment group, daily oral 900 mg allopurinol was started after randomization and maintained for 12 weeks. Brachial artery flow-mediated dilatation (FMD) and nitrate-induced dilatation (NID) were measured at baseline and after the allopurinol therapy to evaluate endothelial function.

RESULTS

HbA1c and uric acid levels decreased after allopurinol therapy (6.1 ± 2.1 vs 5.5 ± 1.0%, 5.0 ± 0.8 vs 3.3 ± 0.5 mg/dl, respectively, p = 0.01) but no change was observed in the placebo group (7.7 ± 1.9% vs 7.6 ± 2.0%, 5.3±2.1 vs 5.6 ± 0.8 mg/dl, respectively, p > 0.05). FMD and NID increased significantly in the treatment group (5.6 ± 2.1% vs 8.5 ± 1.2%, 10 ± 7.4% vs 14 ± 4.0%, 10 ± 7.4% vs 14 ± 4.0%, respectively, p = 0.01), whereas no change was observed in the placebo group (5.8 ± 1.8% vs 6.1 ± 0.8%, 12 ± 9.5 vs 10 ± 3.8%, respectively, p > 0.05).

CONCLUSION

Long-term and high-dose allopurinol therapy significantly improved endothelial function in diabetic normotensive patients. In addition, allopurinol therapy contributes to the lower HbA1c levels.

Relationship between mean platelet volume levels and subclinical target organ damage in newly diagnosed hypertensive patients

BACKGROUND

Significant numbers of asymptomatic hypertensive patients are attacked by subclinical target organ damage (TOD) such as proteinuria, left ventricular hypertrophy and carotid atherosclerosis. Platelets become activated in uncontrolled hypertension and play a crucial role in increased thrombotic tendency. Mean platelet volume (MPV) is one of the markers that correlate closely with platelet activity. We aimed to investigate the relationship between MPV levels and subclinical TOD in newly diagnosed hypertensive patients.

METHODS

80 newly diagnosed hypertensive patients were enrolled to this cross-sectional study. Ambulatory blood pressure monitoring was performed for all patients. Left ventricular mass index (LVMI), carotid intima-media thickness (IMT) and urine albumin/creatinine ratio (UACR) were measured as indices of cardiac, vascular and renal damage, respectively. MPV was measured from blood samples collected in EDTA tubes and high-sensitivity C reactive protein (hs-CRP) was measured by using nephlometer.

RESULTS

MPV was significantly correlated with 24-h systolic-diastolic blood pressure (r = 0.52 and r = 0.55, respectively). Correlation analysis indicated that MPV was moderately related with UACR, LVMI, carotid IMT and hs-CRP (r = 0.50, r = 0.55, r = 0.60 and r = 0.69, respectively, p = 0.0001). Multivariable analysis identified that MPV levels were independently associated with severity of proteinuria, carotid IMT and LVMI (p = 0.001).

CONCLUSION

Our findings suggested that MPV levels were associated with severity of subclinical TOD including; carotid atherosclerosis, left ventricular hypertrophy and renal damage, in hypertensive patients. In addition to this, MPV levels were significantly correlated with hs-CRP levels and 24-h ambulatory blood pressure measurements.

Intravenous N-acetylcysteine plus high-dose hydration versus high-dose hydration and standard hydration for the prevention of contrast-induced nephropathy: CASIS--a multicenter prospective controlled trial

BACKGROUND

Contrast-induced nephropathy (CIN) is a leading cause of acute renal failure and affects mortality and morbidity. We investigated the efficacy of prophylactic intravenous (IV) N-acetylcysteine (NAC) and hydration for the prevention of CIN in patients with mild to moderate renal dysfunction who are undergoing coronary angiography and/or percutaneous coronary intervention (PCI).

METHODS

A total of 220 patients who had mild to moderate renal dysfunction with serum creatinine (SCr) ≥ 1.1mg/dL or creatinine clearance ≤ 60 mL/min were randomized in 3 groups: 80 patients were assigned to IV NAC plus high-dose hydration with normal saline, 80 patients to only high-dose hydration with normal saline and 60 patients to standard hydration with normal saline (control group). The primary end point was the alteration of SCr level. The secondary end point was the development of CIN after the procedure.

RESULTS

SCr levels changed the least in the NAC plus high-hydration group (P=0.004). The rate of the CIN in the NAC plus high-dose hydration group was also lower than the high-dose hydration group (P=0.006). No significant differences in the primary and secondary end points were found between high-dose hydration and control group.

CONCLUSION

The results of this study suggest that NAC plus high-dose hydration was superior to high-dose hydration alone as well as standard hydration for the protection of renal functions in patients with mild to moderate renal dysfunction who are undergoing coronary angiography and/or PCI. High-dose hydration without NAC was not better than standard hydration alone.

Assessment of atrial conduction time in patients with sarcoidosis

OBJECTIVES

Sarcoidosis is an inflammatory granulomatous disease of unknown cause that involves multiple organ systems. Myocardial involvement is usually associated with poor prognosis, but diagnosis of cardiac sarcoidosis is frequently difficult. The aim of this study was to investigate the atrial conduction time in patients with sarcoidosis by using high-usefulness tissue Doppler echocardiography.

METHODS

The study population included 49 patients with sarcoidosis (19 men; mean age, 40.5 ± 9.8 years; mean disease duration, 35.7 ± 15.3 months) and 45 healthy control subjects (17 men; mean age, 40.7 ± 7.2 years). From the 12-lead electrocardiogram, P wave dispersion (PWD) was calculated. The timing of atrial contractions (PA) was measured as the intervals between the onset of P wave on electrocardiogram and the beginning of A-wave on TDI, and atrial electromechanical delay (EMD) was calculated from the lateral (PA lateral) and septal (PA septal) mitral annulus and lateral tricuspid annulus (PA tricuspid).

RESULTS

Both PA lateral and PA septal were significantly longer in patients with sarcoidosis than control subjects (67.9 ± 16.1 vs 56.3 ± 13.1, P < 0.001; and 54.8 ± 15.2 vs 45.1 ± 14.2 ms, P = 0.002, respectively). Intra-atrial (PA septal-PA tricuspid) and interatrial (PA lateral-PA tricuspid) EMD were significantly higher in sarcoidosis groups (12.6 ± 7.5 vs 8.0 ± 7.1, P = 0.003; and 25.7 ± 9.8 vs 19.3 ± 7.7 ms, P = 0.001, respectively). Similarly, maximum P-wave duration and PWD were significantly longer in patients with sarcoidosis than control subjects (105.2 ± 11.8 vs 96.7 ± 15.4, P = 0.004 and 24.7 ± 5.6 vs 19.7 ± 7.1 ms, P = 0.001, respectively). There were significant positive correlations between the disease duration and interatrial EMD (r = 0.56, P < 0.001) and intra-atrial EMD (r = 0.66, P < 0.001). Positive correlation also was present between the disease duration and PWD (r = .62, P < 0.001).

CONCLUSIONS

Atrial EMD was found prolonged in patients with sarcoidosis. We also have demonstrated that PWD, interatrial and intra-atrial EMD were significantly correlated with disease duration. This study calls attention to measurement of atrial conduction time that may be clinically helpful in the recognition of cardiac involvement.

The mean platelet volume in patients with non-dipper hypertension compared to dippers and normotensives

OBJECTIVES

Increased platelet activation plays an important role in the development of atherosclerosis. Mean platelet volume (MPV) is a determinant of platelet activation. In our study, we aimed to determine whether MPV levels are elevated in non-dipper patients compared with dippers and healthy controls. In addition, we tried to find out if MPV levels are correlated with blood pressure measurements in hypertensive patients.

METHODS

This cross-sectional study included 56 hypertensive patients; 27 age- and sex-matched healthy volunteers were enrolled to study as a control subjects. Ambulatory blood pressure monitoring was performed for all patients. Hypertensive patients were divided into two groups: 28 dipper patients (10 male, mean age 51 +/-8 years) and 28 non-dipper patients (11 male, mean age 53+/-10 years). MPV was measured in a blood sample collected in EDTA tubes and was also used for whole blood counts in all patients.

RESULTS

In non-dipper patients, 24-h systolic blood pressure (141.5+/-10.21 vs 132.3+/-7.7 mmHg, p<0.001), 24-h diastolic blood pressure (88.2+/-8.5 vs 81.0+/-8.2 mmHg, p<0.01) and 24-h average blood pressure (105.7+/-8.5 vs 97.7+/-7.4 mmHg, p<0.001) are significantly higher than dippers. Whereas daytime measurements were similar between dippers and non-dippers, there was a significant difference between each group during night-time measurements (night-time systolic 137.1 +/-11.0 vs 120.2+/-8.0 mmHg, p<0.001; night-time diastolic 85.3+/-8.0 vs 72.8+/-7.9 mmHg, p<0.001). Non-dipper patients (9.61 +/-0.42 fl) demonstrated higher levels of MPV compared with dippers (9.24+/-0.35 fl) and normotensives (8.87+/-0.33 fl) (p<0.001 and p<0.001, respectively). There was significant correlation between MPV and ambulatory diastolic and systolic blood pressure in non-dipper hypertensives.

CONCLUSION

Our results suggest that MPV, a determinant of platelet activation, has a positively correlation with blood pressure and elevated in non-dipper compared with dippers and controls. Increased platelet activation could contribute to increase the atherosclerotic risk in non-dipper patients compared with dippers.

Deterioration of heart rate recovery index in patients with systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is an autoimmune disorder resulting in multisystemic inflammatory damage. It is reported that cardiovascular diseases (CVD) are responsible for 20%-30% of deaths in patients with SLE. Heart rate recovery after exercise is a function of vagal reactivation, and its impairment is an independent prognostic indicator for cardiovascular and all-cause mortality. The aim of our study was to evaluate the heart rate recovery index in patients with SLE.

METHODS

The study population included 48 patients with SLE (35 women, mean age 46.3 ± 12.8 yrs, mean disease duration 6.0 ± 2.3 yrs) and 44 healthy controls (30 women, mean age 45.7 ± 12.9 yrs). Basal electrocardiography, echocardiography, and treadmill exercise testing were performed on all patients and controls. The heart rate recovery index was defined as the reduction in the heart rate from the rate at peak exercise to the rate at the first minute (HRR(1)), second minute (HRR(2)), third minute (HRR(3)), and fifth minute (HRR(5)) after stopping exercise stress testing.

RESULTS

There were significant differences in HRR(1) and HRR(2) indices between patients with SLE and the control group (24.1 ± 6.5 vs 33.3 ± 9.3; p < 0.001, and 44.6 ± 13.3 vs 53.7 ± 9.9; p < 0.001, respectively). Similarly, HRR(3) and HRR(5) indices of the recovery period were lower in patients with SLE, compared with indices in the control group (57.6 ± 13.0 vs 64.9 ± 11.7; p = 0.006, and 67.2 ± 12.3 vs 75.0 ± 15.4; p = 0.009, respectively). Effort capacity was markedly lower (9.0 ± 1.9 vs 11.1 ± 2.3 metabolic equivalents; p = 0.001, respectively) among the patients with SLE.

CONCLUSION

The heart rate recovery index is deteriorated in patients with SLE. When the prognostic significance of the heart rate recovery index is considered, these results may contribute to explain the increased occurrence of cardiac death. It points to the importance of the heart rate recovery index in the identification of high-risk patients.

Acute effects of passive smoking on endothelial function

Impairment of endothelial functions has been shown to occur after acute and chronic exposure to passive smoking (PS), as assessed by flow-mediated dilatation (FMD) of the brachial artery. A total of 61 participants, 30 male and 31 female, mean ages 26 (18-36) were enrolled in the study. All were clinically well and nonsmokers. All participants stayed for 30 minutes in the smoking room. Carbon monoxide (CO) level was 7.42 ± 0.98 ppm (4.71-10.50). Mean carboxyhemoglobin (COHb) levels of participants were significantly elevated after PS. Mean FMD was 18.6% ± 9% and decreased to 12.4% ± 7% after PS (P < .001). In the current study, with more number of participants at lower CO concentrations (7.42 ppm) and with smaller increase in COHb (51%) significant reduction (33%, P < .001) in FMD was observed.