Measurement of pulmonary arterial elastance in patients with systolic heart failure using Doppler echocardiography.

OBJECTIVE: A reliable and easy-to-perform method for measuring right ventricular (RV) afterload is desirable when scheduling patients with systolic heart failure to undergo heart transplantation. The present study aimed to investigate the accuracy of echocardiographically-derived pulmonary arterial elastance as a measurement of pulmonary vascular resistance by comparing it with invasive measures. METHODS: Thirty-one patients with moderate to severe systolic heart failure, including 22 (71%) male patients, with a mean age of 41.16 ± 15.9 years were enrolled in the study. Right heart catheterization and comprehensive echocardiography during the first hour after completion of cardiac catheterization were performed in all the patients. The pulmonary artery elastance was estimated using the ratio of end-systolic pressure (Pes) over the stroke volume (SV) by both cardiac catheterization [Ea (PV)-C] and echocardiography [Ea (PV)-E]. RESULTS: The mean Ea (PV)-C and Ea (PV)-E were estimated to be 0.73 ± 0.49 mm Hg/mL and 0.67 ± 0.44 mm Hg/mL, respectively. There was a significant relation between Ea (PV)-E and Ea (PV)-C (r=0.897, p<0.001). Agreement between echocardiography and catheterization methods for estimating Ea (PV), investigated by the Bland-Altman method, showed a mean bias of -0.06, with 95% limits of agreement from -0.36 mm Hg/mL to 0.48 mm Hg/mL. CONCLUSION: Doppler echocardiography is an easy, non-invasive, and inexpensive method for measuring pulmonary arterial elastance, which provides accurate and reliable estimation of RV afterload in patients with systolic heart failure.

Noninvasive localization of accessory pathways in patients with wolff-Parkinson-white syndrome: a strain imaging study.

BACKGROUND: Noninvasive techniques for the localization of the accessory pathways (APs) might help guide mapping procedures and ablation techniques. We sought to examine the diagnostic accuracy of strain imaging for the localization of the APs in Wolff-Parkinson-White syndrome. METHODS: We prospectively studied 25 patients (mean age = 32 ± 17 years, 58.3% men) with evidence of pre-excitation on electrocardiography (ECG). Electromechanical interval was defined as the time difference between the onset of delta wave and the onset of regional myocardial contraction. Time differences between the onset of delta wave (δ) and the onset of regional myocardial contraction (δ-So), peak systolic motion (δ-Sm), regional strain (δ-ε), peak strain (δ-εp), and peak strain rate (δ-SRp) were measured. RESULTS: There was a significant difference between time to onset of delta wave to onset of peak systolic motion (mean ± SD) in the AP location (A) and normal segments (B) versus that in the normal volunteers (C) [A: (57.08 ± 23.88 msec) vs. B: (75.20 ± 14.75) vs. C: (72.9 0 ± 11.16); p value (A vs. B) = 0.004 and p value (A vs. C) = 0.18] and [A: (49.17 ± 35.79) vs. B: (67.60 ± 14.51) vs. C: (67.40 ± 6.06 msec); p value (A vs. B) < 0.001 and p value (A vs. C) = 0.12, respectively]. CONCLUSION: Our study showed that strain imaging parameters [(δ-So) and (δ-Strain)] are superior to the ECG in the localization of the APs (84% vs. 76%).

Risk Factors of Reperfusion Failure following Primary Angioplasty for ST-Segment Elevation Myocardial Infarction (STEMI).

BACKGROUND: Although percutaneous coronary intervention (PCI) improves outcomes compared to thrombolysis, a substantial number of ST-elevation myocardial infarction (STEMI) patients do not achieve optimal myocardial reperfusion. This study was designed to evaluate factors related to suboptimal myocardial reperfusion after primary PCI in patients with STEMI. METHODS: Totally, 155 patients (124 men; mean age = 56.6 ± 11.03 years, range = 31- 85 years) with STEMI undergoing primary PCI were retrospectively studied. Additionally, the relationships between the occurrence of reperfusion failure and variables such as age, sex, cardiac risk factors, family history, Body Mass Index, time of symptom onset, ejection fraction, previous PCI, coronary artery bypass graft surgery or previous myocardial infarction, and angiographic data were analyzed. RESULTS: Procedural success was 97.1% and complete ST resolution occurred in 43.2%. Age; cardiac risk factors; family history; body mass index; previous MI, coronary artery bypass graft surgery, or PCI; and use of thrombectomy device and GPIIb/IIIa inhibitor were not the determining factors (p value > 0.05). According to our multivariate analysis, time of symptom onset (OR [95% CI]: 045 [0.2 to 0.98]; p value = 0.044) and ejection fraction (OR [95% CI]:0.37 [0.26 to .091]; p value = 0.050) had reverse and male gender had direct significant associations with failed reperfusion (OR [95% CI]: 0.34 [0.11 to 1.08]; p value = 0.068). More degrees of ST resolution occurred when the right coronary artery was the culprit vessel (p value = 0.001). The presence of more than three cardiac risk factors was associated with failed reperfusion (p value = 0.050). CONCLUSION: Considering the initial risk profile of patients with acute STEMI, including time of symptom onset and ejection fraction, as well as the accumulation of cardiac risk factors in a given patient, we could predict failed myocardial reperfusion to design a more aggressive therapeutic strategy.

Growth status of Iranian children with hemodynamically important congenital heart disease.

The relationship between congenital heart disease (CHD) and growth retardation is well documented. We investigated the growth condition of Iranian children with several types of congenital heart disease (CHD) and compared it with worldwide researches. Growth condition was investigated in 469 patients with important CHD aged from 1 month to 18 years. The patients were divided into two groups; infants (aged 12 months or less), and children (1-18 yrs of age). Children with hemodynamically unimportant small VSDs or small ASDs were not studied. Other exclusion criteria were prematurity, known genetic disorders and neurologic disease affecting growth. All patients' cardiac diagnoses were made on the basis of clinical and laboratory examinations; including electrocardiography, echocardiography, cardiac catheterization, and angiography. Body weight and height of all patients were measured using conventional methods and compared with standard growth charts. In all patients body weights and heights were significantly lower than normal population. This difference was greater in the weight of female children. Other risk factors for growth failure were large left-to-right intracardiac shunts, pulmonary hypertension and cyanosis. Iranian children with CHD have growth failure somewhat different from other countries. Lower body weights of cyanotic patients and female children indicated that these patients need more nutritional and psychosocial attention.

Physician-related factors affecting cardiac rehabilitation referral.

BACKGROUND: Despite the positive impact of cardiac rehabilitation (CR) on quality of life and mortality, the majority of people who could benefit from this program fail to participate in it. The lack of referral from the physician is a common reason that patients give for not seeking CR. The objective of this study was to compare factors affecting CR referral by cardiologists. METHODS: A cross-sectional survey of 122 cardiologists, including 89 general cardiac specialists and 33 fellows in cardiology from 11 major cardiology training centers in Iran, was done in 2010. They responded to the 14- item investigator-generated survey, examining the physician's attitudinal and knowledge factors affecting CR referral. RESULTS: 47.9% of the subjects reported having available CR centers but only 6.6% reported continuous medical education on the topic. 90.7% of the physicians reported that less than 15% of patients are referred to CR centers. The main factor affecting the low referral rate was limited general knowledge about CR programs (79.5%) such as program attributes and benefits, methods of reimbursement. Lack of insurance coverage, unavailability of CR centers in the community and low physicians' fee were other factors reported by the physicians. CONCLUSION: Cardiologists' inadequate general knowledge of and attitude toward CR programs seem to be a potential threat for cardiac prevention and rehabilitation in some societies.

Is the Peak-to-Mean Pressure Gradient Ratio Useful for Assessment of Aortic Valve Prosthesis Obstruction?

BACKGROUND: The evaluation of prosthetic valves is very difficult with two-dimensional transthoracic echocardiography alone. Doppler and color flow imaging as well as transesophageal echocardiography are more reliable to detect prosthetic valve dysfunction. However, Doppler study sometimes tends to be misleading due to the load-depending characteristics of peak and mean pressure gradients. The peak-to-mean pressure decrease ratio is a load-independent measure, which was previously used for the detecting and grading of aortic valve stenosis. We assessed the usefulness of this method for the evaluation of aortic valve prosthesis obstruction. METHODS: One hundred fifty-four patients with aortic valve prostheses were included in this study. Transthoracic and transesophageal echocardiographic examinations were performed in all the patients. Peak velocity and velocity time integral of the aortic valve and left ventricular outflow tract, peak and mean aortic valve pressure gradients, peak-to-mean pressure gradient ratio, and time velocity integral (TVI) index were measured. RESULTS: There was a significant relation between the TVI index (p value < 0.001) and aortic prosthesis obstruction. A TVI index < 0.2 had a sensitivity of 71% and specificity of 100% for the detection of aortic valve prosthesis obstruction. However, no significant relation was found between the peak-to-mean pressure ratio and aortic valve prosthesis obstruction (p value = 0.09). CONCLUSION: Although the peak-to-mean pressure gradient (PG/MG) ratio is a simple, quick, and load-independent method which may be useful for the grading of aortic valve stenosis, it is poorly associated with aortic valve prosthesis obstruction. The TVI index is a useful measure for the detection of aortic prosthesis obstruction.

Predictors of ventricular tachycardia induction in syncopal patients with mild to moderate left ventricular dysfunction.

BACKGROUND: In patients with mild to moderate left ventricular dysfunction (LVD) (35% pound LVEF pound 50%) who present with syncope, demonstration of tachy and/or brady-arrhythmia has prognostic value. In this group of patients electrophysiological study (EPS) is often necessary. METHODS: A total of 53 consecutive patients with mild to moderate LVD and history of undetermined syncope underwent EPS. Sinus node function, His-Purkinje system conduction and ventricular electrical stability were evaluated. RESULTS: Twenty eight patients (52.8%) had induction of sustained monomorphic ventricular tachycardia (VT) and five (9.4%) patients had a sustained ventricular arrhythmia other than monomorphic VT (ventricular flutter, ventricular fibrillation, and polymorphic VT) induced during EPS. Abnormal sinus node function and/or His-Purkinje system conduction was found in five (9.4%) patients. Age, gender, history of myocardial infarction, type of underlying heart disease and history of revascularization were not predictors of VT induction. Wide QRS morphology independently, and lower left ventricular ejection fraction and presence of pathologic q wave in precordial leads dependently, could increase risk of VT induction. CONCLUSIONS: The EPS can determine which patient with syncope and mild to moderate LVD is likely to benefit from placing an ICD for prevention of sudden cardiac death. Pathologic precordial q wave, wide QRS morphology and lower left ventricular ejection fraction could be predictors of VT induction during EPS. Wide QRS morphology has an independent effect in this category.

Can prodromal symptoms predict recurrence of vasovagal syncope?

BACKGROUND: Vasovagal syncope (VVS) is a common symptom with empirical therapy and high recurrence rate. Our goal was to determine whether the pattern of presyncopal prodromal symptoms can predict the recurrence probability of vasovagal syncope. METHODS: Seventy-nine consecutive patients (male/female: 53/26) with history of VVS and positive tilt table test (TTT) were enrolled in the study and completed the follow-up time for one year. They all had normal electrocardiograms and cardiac echocardiography without underlying disease. All of them were evaluated meticulously for prodromal symptoms (diaphoresis, nausea, palpitation and blurred vision) and frequency of syncopal spells in their past medical history. They received metoprolol at maximum tolerated dose and were taught tilt training as an empirical therapy after TTT. RESULTS: Fifty-four patients (68.4%) reported at least one of the four main prodromal symptoms. Median syncopal +/- presyncopal spells were 4 episodes. Forty-two patients (53.2%) experienced recurrence of syncope or presyncope during the follow-up period. In recurrent symptomatic patients, diaphoresis had been more significantly reported in their past medical history (p = 0.018) and they had more syncopal spells before TTT (p = 0.001). Age, gender and type of TTT response did not have any effect on the recurrence of VVS. CONCLUSIONS: Patients with a history of diaphoresis as a prodromal symptom and more pretilt syncopal attacks experience more syncopal or presyncopal spells during follow-up.

Relationship between QRS complex notch and ventricular dyssynchrony in patients with heart failure and prolonged QRS duration.

BACKGROUND: Cardiac resynchronization therapy (CRT) has been accepted as an established therapy for advanced systolic heart failure. Electrical and mechanical dyssynchrony are usually evaluated to increase the percentage of CRT responders. We postulated that QRS notch can increase mechanical LV dyssynchrony independently of other known predictors such as left ventricular ejection fraction and QRS duration. METHODS: A total of 87 consecutive patients with advanced systolic heart failure and QRS duration more than 120 ms with an LBBB-like pattern in V1 were prospectively evaluated. Twelve-lead electrocardiogram was used for detection of QRS notch. Complete echocardiographic examination including tissue Doppler imaging, pulse wave Doppler and M-mode echocardiography were done for all patients. RESULTS: Eighty-seven patients, 65 male (75%) and 22 female (25%), with mean (SD) age of 56.7 (12.3) years were enrolled the study. Ischemic cardiomyopathy was the underlying heart disease in 58% of the subjects, and in the others it was idiopathic. Patients had a mean (SD) QRS duration of 155.13 (23.34) ms. QRS notch was seen in 49.4% of the patients in any of two precordial or limb leads. Interventricular mechanical delay was the only mechanical dyssynchrony index that was significantly longer in the group of patients with QRS notch. Multivariate analysis revealed that the observed association was actually caused by the effect of QRS duration, rather than the presence of notch per se. CONCLUSIONS: QRS notch was not an independent predictor of higher mechanical dyssynchrony indices in patients with wide QRS complex and symptomatic systolic heart failure; however, there was a borderline association between QRS notch and interventricular delay.