Low atrial natriuretic factor levels and absent pulmonary edema in pericardial compression of the heart

Left Atrial Remodeling Related to Disproportionately Low B-Type Natriuretic Peptide in Acute Heart Failure Patients with Atrial Fibrillation

The diagnostic performance of B-type natriuretic peptide (BNP) for acute heart failure (HF) is impaired in patients with atrial fibrillation (AF). Increased AF burden in HF is associated with left atrial (LA) remodeling. Recent studies have revealed that LA remodeling may affect LV filling. We hypothesized that LA remodeling affects BNP secretion in acute HF conditions. The study investigated the clinical impact of LA remodeling on admission BNP levels in acute HF patients with and without AF. Consecutive acute HF hospitalized patients (n = 899) were divided into groups with (n = 382) or without AF (n = 507) and subdivided into disproportionately low BNP (LB) (≤200 pg/ml), medium BNP (200 to 600 pg/ml) and high BNP (≥600 pg/ml) subgroups. The AF group had a higher proportion of patients with LB than the non-AF group (23.6% vs 16.6%, p = 0.009). BNP levels in both groups were positively correlated with LV end-diastolic volume and negatively correlated with LV ejection fraction in both groups. In contrast, BNP was positively correlated with LA volume index in the non-AF group, but negatively correlated in the AF group. The survival rates were significantly higher in the LB group than in the other groups in non-AF. Conversely, there were no significant differences across all groups in AF patients. In conclusion, in patients with acute HF and AF, disproportionately low BNP levels are associated with LA structural remodeling and poor prognosis.

Disproportionately low BNP levels in patients of acute heart failure with preserved vs. reduced ejection fraction

BACKGROUND

B-type natriuretic peptide (BNP) has been widely used for the diagnosis of heart failure, its severity, and prognosis. However, little is known about factors related to disproportionately low BNP levels even during acute heart failure conditions.

METHODS AND RESULTS

Among 424 patients hospitalized for acute heart failure, we categorized the patients into the HFpEF (LVEF > 50%) or HFrEF (LVEF ≤ 50%) group and subdivided them into disproportionately low BNP (LB) group and high BNP (HB) group using a cut-off BNP level of 200 pg/mL at admission. The proportion of patients with LB was higher in the HFpEF group (22.2%) than in the HFrEF group (10.9%, p = 0.002). Patients with LB had a high BMI, lower blood pressure, and history of previous cardiovascular surgery in the HFpEF group, while patients in the HFrEF group had a high BMI and smaller left ventricular end-diastolic volume index. Furthermore, presence of LB in the HFrEF group was related to good prognosis, but LB in the HFpEF group was an indicator of poor prognosis as HB group.

CONCLUSIONS

The factors associated with LB were different between the HFpEF and HFrEF groups. LB was related to good prognosis in HFrEF, but not in HFpEF.

Tamponade: Hemodynamic and Echocardiographic Diagnosis

Cardiac tamponade is a medical emergency that can be readily reversed with timely recognition and appropriate intervention. The clinical diagnosis of cardiac tamponade requires synthesis of a constellation of otherwise nonspecific features based on an understanding of the underlying pathophysiological characteristics. Although echocardiographic examination is a central component of diagnosis, alone it is insufficient to establish the physiological diagnosis of hemodynamically significant cardiac tamponade. The hemodynamic diagnosis of cardiac tamponade requires clinical evidence of low cardiac output and stroke volume in the setting of elevated cardiac filling pressures, with evidence of increased sympathetic tone (eg, tachycardia, peripheral vasoconstriction), and exclusion of other causes of shock as the primary problem (particularly cardiogenic shock). The hemodynamic features of tamponade are revealed by considering the effects of pericardial constraint. Pulsus paradoxus and loss of the normal "y" descent of a jugular venous pressure waveform may be appreciated on clinical examination. When a pulmonary artery catheter is placed, equalization of diastolic pressures across all chambers is observed. Echocardiographic examination confirms the size, location, and other characteristics of the causal pericardial collection. Several echocardiographic features support the hemodynamic diagnosis of tamponade, including early diastolic collapse of the right ventricle, late diastolic collapse of the right atrium, respiratory variation in mitral valve inflow (akin to pulsus paradoxus), and decreased early filling (E wave) of mitral valve inflow (related to loss of the y descent). Echocardiographic examination then supports decisions about the early treatment and drainage of the tamponading effusion.

Heart failure in children in tropical regions

With the ever increasing younger population in tropical countries, the number of children with heart failure is increasing. However, the etiology of heart failure in this region varies considerably from that in the temperate region, with infectious causes leading the list. In this review, we have summarized the important causes of heart failure seen in the pediatric population in tropical regions.

Characteristics of acute congestive heart failure with normal ejection fraction and less elevated B-type natriuretic peptide

BACKGROUND

Heterogeneity in B-type natriuretic peptide (BNP) levels, especially among individuals with acute heart failure with normal left ventricular ejection fraction (HFNEF), can cause confusion in interpreting results. We investigated the characteristics of cases of acute HFNEF with only modestly elevated BNP.

METHODS

One hundred forty-two patients with acute or acute exacerbation of chronic HFNEF were divided into two groups by BNP level: BNP < 100 pg/ml (NB group, n = 45) and BNP > or = 100 pg/ml (B group, n = 97). We compared clinical findings, echocardiography results, and neurohormonal factors between these two groups.

RESULTS

In the NB group, a history of open-heart surgery (OHS) was more frequent (71% vs. 22%, p < 0.0001) and hypertension was less frequent (p = 0.0005). Left atrial diameter (LAd) was higher (p = 0.0026), while interventricular septal thickness, posterior wall thickness, relative wall thickness, left ventricular mass index were lower (p = 0.0005, p = 0.0225, p = 0.0114, p = 0.0051, respectively) in the NB group. In patients with HFNEF, a history of OHS remained an independent predictor of BNP level (< 100 pg/ml) after adjustment for hypertension, age, LAd, and interventricular septal thickness (odds ratio 3.6, p = 0.0252).

CONCLUSION

We found associations between acute HFNEF with less elevated BNP and a history of OHS. In a patient suspected of HFNEF, a history of OHS is considered diagnostic evidence of presence of diastolic heart failure when plasma levels of BNP are less elevated.

N-terminal pro-B-type natriuretic peptide as a marker of disease severity in patients with pericardial effusions

BACKGROUND/AIMS

N-terminal pro-B-type natriuretic peptide (NT-proBNP) has recently been introduced as a useful marker in diagnosing underlying disease in patients with dyspnea and for determining the prognosis of patients with heart failure. The purpose of this study was to evaluate the value of the NT-proBNP as a marker of disease severity in patients with pericardial effusions.

METHODS

We enrolled 69 consecutive patients who showed moderate or large pericardial effusion with preserved left ventricular (LV) systolic function; 42 patients finally participated in the study, and 13 (31.0%) of them showed cardiac tamponade. We analyzed the etiologies, the clinical and echocardiographic variables, and the serum NT-proBNP levels in these patients.

RESULTS

The mean NT-proBNP level was 751+/- 1002 ng/L (range 5 to 5289), and the median level was 385 ng/L (interquartile range 152 to 844). The NT-proBNP levels were higher in those patients with jugular venous distension (p=0.002), pulsus paradoxus (p=0.016), heart rate > or = 100/min (p=0.006), cardiac tamponade (p=0.001), large pericardial effusion (p=0.029), exaggerated respiratory variation of the transmitral inflow (p=0.006), or plethora of the inferior vena cava (p=0.01). The NT-proBNP levels showed significant correlation with heart rate (r=0.517, p<0.001) and the diameter of the inferior vena cava (r=0.329, p=0.03).

CONCLUSIONS

NT-proBNP may be useful as a marker of disease severity in patients suffering from pericardial effusion, but further prospective studies with more patients will be needed.

B-type natriuretic peptide level in a patient with constrictive pericarditis

We report the case of a 35-year-old man with constrictive pericarditis who had a B-type natriuretic peptide (BNP) level of 129 pg/dl despite a left ventricular end diastolic pressure of 35 mmHg. We discuss a possible explanation for the relatively low BNP level given this patient's markedly elevated intracavitary pressures in the setting of constrictive pericarditis.

Pathogenesis of edema in constrictive pericarditis. Studies of body water and sodium, renal function, hemodynamics, and plasma hormones before and after pericardiectomy

BACKGROUND

The pathogenesis of sodium and water accumulation in chronic constrictive pericarditis is not well understood and may differ from that in patients with chronic congestive heart failure due to myocardial disease. This study was undertaken to investigate some of the mechanisms.

METHODS AND RESULTS

Using standard techniques, the hemodynamics, water and electrolyte spaces, renal function, and plasma concentrations of hormones were measured in 16 patients with untreated constrictive pericarditis and were measured again in eight patients after pericardiectomy. The average hemodynamic measurements were as follows: cardiac output, 1.98 l/min/m2; right atrial pressure, 22.9 mm Hg; pulmonary wedge pressure, 24.2 mm Hg; and mean pulmonary artery pressure 30.2 mm Hg. The systemic and pulmonary vascular resistances (36.3 +/- 2.5 and 3.2 +/- 0.3 mm Hg.min.m2/l, respectively) were increased. Significant increases occurred in total body water (36%), extracellular volume (81%), plasma volume (53%), and exchangeable sodium (63%). The renal plasma flow was only moderately decreased (49%), and the glomerular filtration rate was normal. Significant increases also occurred in plasma concentrations of norepinephrine (3.6 times normal), renin activity (7.2 time normal), aldosterone (3.4 times normal), cortisol (1.4 times normal), growth hormone (21.8 times normal), and atrial natriuretic peptide (5 times normal). The ratio of left atrial to aortic diameter measured by echocardiography was only minimally increased (1.29 +/- 0.04), indicating that in constrictive pericarditis the atria are prevented from expanding. The studies repeated after pericardiectomy in the eight patients showed that all measurements returned toward normal.

CONCLUSIONS

The restricted distensibility of the atria, in constrictive pericarditis, limits the secretion of atrial natriuretic factor and, thus, reduces its natriuretic and diuretic effects. This results in retention of water and sodium greater than that occurring in patients with edema from myocardial disease. The arterial pressure is maintained more by the expansion of the blood volume than by an increase in the peripheral vascular resistance.