Relationship between exercise induced elevation of left ventricular filling pressure and exercise intolerance in patients with atrial fibrillation.

BACKGROUND: Elevated left ventricular filling pressure (LVFP) is an important cause of exercise intolerance in patients with atrial fibrillation (AF). Exercise stress echocardiography could assess LVFP during exercise. The objective of this study was to investigate the relationship between exercise induced elevation of LVFP and exercise capacity in patients with AF. METHODS: This study included 145 consecutive patients (81 men and 64 women; mean age 65.5 ± 8.0 years) with persistent non-valvular AF and normal left ventricular systolic function (left ventricular ejection fraction ≥ 50%). All patients underwent a symptom-limited cardiopulmonary exercise test (CPET). Doppler echocardiography was performed both at rest and immediately after exercise. Five consecutive measurements of early diastolic mitral inflow velocity (E) and early diastolic mitral annular velocity (e') were taken and averaged. E/e' ratio was calculated. Elevated LVFP was defined as E/e' > 9, and patients with elevated LVFP at rest were excluded. RESULTS: Patients were classified into two groups according to LVFP estimated by E/e' ratio after exercise: 39 (26.9%) with elevated LVFP after exercise and 106 (73.1%) with normal LVFP. As compared with patients with normal LVFP, the ones with elevated LVFP after exercise had significantly lower peak oxygen uptake (VO2 peak) (21.7 ± 2.3 vs. 26.4 ± 3.8 mL/min per kilogram, P < 0.001), lower anaerobic threshold (19.9 ± 2.5 vs. 26.0 ± 4.0 mL/min per kilogram, P < 0.001), and shorter exercise time duration (6.2 ± 0.8 vs. 7.0 ± 1.3 min, P < 0.001). Multivariate analysis showed that age, gender and E/e' after exercise were significantly correlated with VO2 peak. CONCLUSION: Elevated LVFP estimated by E/e' ratio after exercise is independently associated with reduced exercise capacity in AF patients.

Correlation between growth differentiation factor-15 and collagen metabolism indicators in patients with myocardial infarction and heart failure.

BACKGROUND: Growth differentiation factor (GDF)-15, a divergent member of the transforming growth factor beta super-family does appear to be up-regulated in response to experimental pressure overload and progression of heart failure (HF). HF frequently develops after myocardial infarction (MI), contributing to worse outcome. The aim of this study is to assess the correlation between GDF-15 levels and markers related to collagen turnover in different stages of HF. METHODS: The study consists of a cohort of 179 patients, including stable angina pectoris patients (AP group, n = 50), old MI patients without HF (OMI group, n = 56), old MI patients with HF (OMI-HF group, n = 38) and normal Control group (n = 35). Both indicators reflecting the synthesis and degradation rates of collagen including precollagen I N-terminal peptide (PINP), type I collagen carboxy-terminal peptide (ICTP), precollagen III N-terminal peptide (PIIINP) and GDF-15 were measured using an enzyme-linked inmunosorbent assay. RESULTS: The plasma GDF-15 level was higher in OMI-HF group (1373.4 ± 275.4 ng/L) than OMI group (1036.1 ± 248.6 ng/L), AP group (784.6 ± 222.4 ng/L) and Control group (483.8 ± 186.4 ng/L) (P < 0.001). The indicators of collagen turnover (ICTP, PINP, PIIINP) all increased in the OMI-HF group compared with Control group (3.03 ± 1.02 µg/L vs. 2.08 ± 0.95 µg/L, 22.2 ± 6.6 µg/L vs. 16.7 ± 5.1 µg/L and 13.2 ± 7.9 µg/L vs. 6.4 ± 2.1 µg/L, respectively; P < 0.01). GDF-15 positively correlated with ICTP and PIIINP (r = 0.302, P < 0.001 and r = 0.206, P = 0.006, respectively). GDF-15 positively correlated to the echocardiographic diastolic indicators E/Em and left atrial pressure (r = 0.349 and r = 0.358, respectively; P < 0.01), and inversely correlated to the systolic indicators left ventricular ejection fraction and the average of peak systolic myocardial velocities (Sm) (r = -0.623 and r = -0.365, respectively; P < 0.01). CONCLUSION: Plasma GDF-15 is associated with the indicators of type I and III collagen turnover.

[Anorexia with sinus bradycardia: a case report].

As anorexia patients always go to the psychiatric clinic, little is concerned about the occurrence of sinus bradycardia in these patients for cardiologists and psychiatrists. The aim of this paper is to discuss the relationship between anorexia and sinus bradycardia, and the feature analysis, differential diagnosis and therapeutic principles of this type of sinus bradycardia. We report a case of sinus bradycardia in an anorexia patient with the clinical manifestations, laboratory exams, auxiliary exams, therapeutic methods, and her prognosis, who was admitted to Peking University Third Hospital recently. The patient was a 19-year-old female, who had the manifestation of anorexia. She lost obvious weight in a short time (about 15 kg in 6 months), and her body mass index was 14.8 kg/m(2). The patient felt apparent palpitation, chest depression and short breath, without dizziness, amaurosis or unconsciousness. Vitals on presentation were notable for hypotension, and bradycardia. The initial exam was significant for emaciation, but without lethargy or lower extremity edema. The electrocardiogram showed sinus bradycardia with her heart rate being 32 beats per minute. The laboratory work -up revealed her normal blood routine, electrolytes and liver function. But in her thyroid function test, the free thyroid (FT) hormones 3 was 0.91 ng/L (2.3-4.2 ng/L),and FT4 was 8.2 ng/L (8.9-18.0 ng/L), which were all lower; yet the thyroid stimulating hormone (TSH) was normal 1.48 IU/mL (0.55-4.78 IU/mL). Ultrasound revealed her normal thyroid. Anorexia is an eating disorder characterized by extremely low body weight, fear of gaining weight or distorted perception of body image, and amenorrhea. Anorexia patients who lose weight apparently in short time enhance the excitability of the parasympathetic nerve, and inhibit the sympathetic nerve which lead to the appearance of sinus bradycardia, and functional abnormalities of multiple systems such as hypothyroidism. But this kind of sinus bradycardia and hypothyroidism have good prognosis. And asymptomatic sinus bradycardia with reversible causes, because of the great prognosis, they do not need special treatment. Multiple medical and psychiatric disciplines were consulted, and then, family care, nutritional support and psychiatric therapy were given, and she did not need thyroid hormone replacement therapy. The patient's overall clinical status improved gradually during her hospital stay and her heart rate was recovered to 55 beats per minute.

[Evaluation of arterial elasticity in initial hypertension by pulse wave velocity and wave intensity technique].

OBJECTIVE: To explore the early changes of arterial elasticity in initial hypertension through two different methods. METHODS: A total of 76 hypertensive patients (Grade 1-2, n = 32) were assigned into hypertension group while the age and gender-matched healthy population was selected as normal group (n = 44). All of them were monitored for baPWV in right carotid artery by wave intensity technique. The parameters of two methods were compared between two groups. RESULTS: Higher bi-lateral baPWV were found in the hypertension group (right: (1472 ± 198) m/s vs (1353 ± 233) m/s), (left: (1465 ± 198) m/s vs (1353 ± 241) m/s) (P < 0.05). Compared with the normal group, Patients in the hypertension group had statistically higher W(1) ((9.8 ± 3.8)×10(3) mm Hg×m×s(-3) vs (7.4 ± 2.4)×10(3)) mm Hg×m×s(-3), W(2) ((2.8 ± 1.1)×10(3) mm Hg×m×s(-3) vs (2.0 ± 1.0)×10(3) mm Hg×m×s(-3)), stiffness parameter (ß) ((6.9 ± 2.6) vs (5.1 ± 1.3)), pressure-strain elastic modulus (Ep) ((99 ± 39) kPa vs (57 ± 17) kPa), one-point wave velocity (PWVß) ((6.0 ± 1.1) m/s vs (4.6 ± 0.6) m/s), PWVWI ((6.2 ± 1.4) m/s vs (4.4 ± 1.0) m/s) (P < 0.01). R-W(1) ((100 ± 14) ms vs (103 ± 13) ms), (W(1)-W(2)) ((261 ± 20) ms vs (274 ± 15) ms) and arterial compliance (AC) ((0.8 ± 0.4) mm(2)/kPa vs (1.1 ± 0.3) mm(2)/kPa) in the hypertension group were statistically lower than those of the normal group (P < 0.05). CONCLUSION: The initial hypertensive patients may have impaired arterial elasticity during an early stage.

[The evaluation of left ventricular diastolic function by tissue Doppler echocardiography in essential hypertension].

OBJECTIVE: To evaluate Left ventricular(LV) diastolic function in essential hypertension by conventional pulse-wave Doppler echocardiography (cPWD) and Doppler tissue imaging (DTI) and compare the two modalities. METHODS: Two hundred patients with essential hypertension were classified as NLVH subgroup (n = 160) and LVH subgroup (n = 40) based on left ventricular mass index (LVMI) with one hundred and sixty health subjects as control group. The mitral valve flow pattern (MVFP) was obtained.Early diastolic (E) and late velocities (A) were measured and E/A was calculated. DTI was used to obtain the left ventricular lateral wall early diastolic mitral annulus velocity (Em) and E/Em was calculated. RESULTS: Essential hypertension patients had LV diastolic dysfunction both by cPWD (higher E and lower E/A ratio) and DTI (lower Em and higher E/Em ratio) compared with healthy subjects [E: (0.88 ± 0.18) cm/s vs (0.76 ± 0.19) cm/s; E/A ratio: 0.86 ± 0.28 vs 1.02 ± 0.38; Em: (9.4 ± 2.8) cm/s vs (11.9 ± 3.8) cm/s; E/Em ratio: 7.9 ± 2.7 vs 6.0 ± 1.8: with all P value < 0.01]. Em was significantly reduced and E/Em was significantly elevated in LVH subgroup than NLVH subgroup [Em: (7.7 ± 2.6) cm/s vs (9.9 ± 2.8) cm/s, E/Em:9.6 ± 3.6 vs 7.4 ± 2.4, P < 0.05]. No significant difference was found in A and E/A between these two subgroups [(0.90 ± 0.22) cm/s vs (0.87 ± 0.17) cm/s; 0.80 ± 0.34 vs 0.88 ± 0.28, P > 0.05]. CONCLUSIONS: cPWD and DTI both had implications to detect diastolic dysfunction in non-hypertrophic stage hypertension. Em, E/Em could be more sensitive and precise to reflect the impairment of diastolic function in the progress of hypertension.

[Prognostic values for in-hospital event rate of early E/Em in patients with acute myocardial infarction].

OBJECTIVE: To assess the prognostic values for in-hospital event rate of tissue Doppler imaging (TDI) parameter (E/Em) after acute myocardial infarction. METHODS: A total of 289 patients with acute myocardial infarction were retrospectively examined. Their clinical data and echocardiograms were obtained. Clinical events were recorded. Patients were divided into two groups according to the value of ratio of early transmitral flow velocity to early diastolic velocity of mitral annulus (E/Em): Group E/Em < 10 (n = 152) and Group E/Em ≥ 10 (n = 137). Clinical characteristics, echocardiographic parameters and the rate of cardiac events were compared. Predictors of heart failure were identified by multivariate Logistic regression analysis. RESULTS: On echocardiography, the patients with an E/Em ratio ≥ 10 had statistically larger left atrial diameter [(39.1 ± 6.2) vs (36.0 ± 4.4) mm, P = 0.000] and left ventricular end diastolic diameter [(52.3 ± 7.3)vs (49.2 ± 5.2) mm, P = 0.000]. Worse systolic functions were found in group E/Em ≥ 10: left ventricular ejection fraction (LVEF) [(48.3 ± 11.7)% vs (56.7 ± 9.7)%, P = 0.000]. Systolic velocities of mitral annulus (Sm) [(6.6 ± 1.7) vs (8.6 ± 2.2) cm/s, P = 0.000]. Em [(6.4 ± 1.9) vs (9.4 ± 2.4) cm/s, P = 0.000] was statistically lower than that of E/Em < 10 group. Killip classes on admission were statistically higher in group E/Em ≥ 10 than those of the other group [(1.7 ± 0.9) vs (1.2 ± 0.6), P = 0.000]. So were as the ratio of heart failure (38.5% vs 13.8%, P = 0.000) and in-hospital mortality rate (4.4% vs 0.8%, P = 0.000). Logistic regression analysis demonstrated that the independent risk factors of heart failure included the value of E/Em and LVEF. CONCLUSION: Early E/Em is probably a powerful predictor for left ventricular remodeling and in-hospital heart failure in patients after acute myocardial infarction.