Etiological classification and manifestation of pulmonary artery dissection: A literature review and case analysis.

Background: Pulmonary artery dissection (PAD) is an uncommon condition associated with high mortality rates. To date, a comprehensive examination of various underlying causes of PAD remains unexplored. Methods: We used the search words "pulmonary artery dissection," "pulmonary artery dilatation," and "pulmonary artery rupture" in the public database, and examined the medical records of PAD patients treated in our hospital. Data on demographics, aetiology, PAD locations, histopathology, treatments, and outcomes, were collected. Results: A total of 145 patients with PAD (135 cases from the literature and 10 cases from our hospital) were analysed. PAD aetiology was categorized into four groups: congenital heart diseases (CHD) associated with pulmonary arterial hypertension (PAH), non-CHD associated with pulmonary hypertension (PH), aortic dissection-related, and miscellaneous causes. The most frequent cause, accounting for 32.4 % of PAD cases, was congenital heart disease, followed by idiopathic PAH (13 %) and chronic obstructive pulmonary disease (6 %). Patients with CHD were typically younger at the time of PAD diagnosis (median age: 35 years old) when compared with those suffering from aortic dissection, PH-associated conditions, or other causes (median age: 45, 55, and 56 years old, respectively). Imaging of the pulmonary artery proved effective in diagnosing PAD. The outcomes were generally poor. 44.7 % (21/47) of patients with CHD associated with PAH and 47.7 % (21/44) of non-CHD PH-associated diseases died during follow-up. Multidisciplinary team consultations are crucial when making decisions on management of PAD. Characteristic PAD histopathology features included thickened intima and hypertrophied media with atheromatous degeneration, disrupted elastic fibres, and lymphocytic infiltration. Conclusions: PAD aetiology can be divided into four main categories, with CHD associated with PAH being the leading cause. Despite the similar histopathology features, clinical manifestations and outcomes vary according to the aetiology.

A case report of a long-term survivor after inadvertent ligation of the left pulmonary artery during intended ductal ligation.

Background: Patent ductus arteriosus (PDA) can close on its own during childhood. Patent ductus arteriosus with left pulmonary artery (LPA) occlusion is rare. Here, we describe possible aetiologies of this condition and treatment strategies based on recent guidelines. Case summary: A 35-year-old man experienced shortness of breath for 20 years. Physical examination revealed pitting oedema, digital clubbing, and bi-phasic murmur along the left sternal border at the 2nd and 3rd intercostal space. Congenital heart disease was suspected. Echocardiography revealed a severely dilated pulmonary trunk and PDA; however, the LPA was not visible. The patient has undergone PDA ligation surgery >30 years ago, which may have caused accidental LPA ligation; however, extreme elevation of pulmonary pressure led to increased difficulties in performing LPA reconstruction and PDA division. Therefore, pulmonary arterial hypertension (PAH) initial combination therapy with parenteral prostanoids was prescribed. The patient's condition improved gradually. Discussion: Inadvertent ligation of the LPA instead of PDA is a rare and usually fatal complication during ductal ligation. Patients who survive this catastrophic complication usually develop the progressive pulmonary vascular disease with increased pulmonary pressure and impaired lung parenchyma resulting in right heart and respiratory failure. Early and regular follow-up with cardiac imaging studies is important to diagnose this complication. Reconstruction of the ligated LPA and PDA late in the disease course is difficult due to the development of pulmonary arterial hypertension. Initial PAH combination therapy may be valuable for relieving the patients' symptoms at that stage. Heart and lung transplantation can also be considered in suitable patients.

Inhibition of the RhoA/Rho-associated, coiled-coil-containing protein kinase-1 pathway is involved in the therapeutic effects of simvastatin on pulmonary arterial hypertension.

BACKGROUND: Recent research has shown that statins improve pulmonary arterial hypertension (PAH), but their mechanisms of action are not fully understood. This study aimed to investigate the role of RhoA/ROCK1 regulation in the therapeutic effects of simvastatin on PAH. METHODS: For in vivo experiments, rats (N = 40) were randomly assigned to four groups: control, simvastatin, monocrotaline (MCT), and MCT + simvastatin. The MCT group and MCT + simvastatin groups received proline dithiocarbamate (50 mg/kg, i.p.) on the first day of the study. The MCT + simvastatin group received simvastatin (2 mg/kg) daily for 4 weeks, after which pulmonary arterial pressure was measured by right heart catheterization. The protein and mRNA levels of Rho and ROCK1 were measured by immunohistochemistry, Western blot, and PCR. For in vitro experiments, human pulmonary endothelial cells were divided into seven groups: control, simvastatin, monocrotaline pyrrole (MCTP), MCTP + simvastatin, MCTP + simvastatin + mevalonate, MCTP + simvastatin + farnesyl pyrophosphate (FPP), and MCTP + simvastatin + FPP + geranylgeranyl pyrophosphate (GGPP). After 72 h exposed to the drugs, the protein and mRNA levels of RhoA and ROCK1 were measured by Western blot and PCR. RESULTS: The MCT group showed increased mean pulmonary arterial pressure, marked vascular remodeling, and increased protein and mRNA levels of RhoA and ROCK1 compared to the other groups (P < 0.05). In vitro, the MCTP group showed a marked proliferation of vascular endothelial cells, as well as increased protein and mRNA levels of RhoA and ROCK1 compared to the MCTP + simvastatin group. The MCTP + simvastatin + mevalonate group, MCTP + simvastatin+ FPP group, and MCTP + simvastatin + FPP + GGPP group showed increased mRNA levels of RhoA and ROCK1, as well as increased protein levels of RhoA, compared to the MCTP + simvastatin group. CONCLUSIONS: Simvastatin improved vascular remodeling and inhibited the development of PAH. The effects of simvastatin were mediated by inhibition of RhoA/ROCK1. Simvastatin decreased RhoA/ROCK1 overexpression by inhibition of mevalonate, FPP, and GGPP synthesis.

Pulmonary function differences in patients with chronic right heart failure secondary to pulmonary arterial hypertension and chronic left heart failure.

BACKGROUND: Pulmonary abnormalities are found in both chronic heart failure (CHF) and pulmonary arterial hypertension (PAH). The differences of pulmonary function in chronic left heart failure and chronic right heart failure are not fully understood. MATERIAL AND METHODS: We evaluated 120 patients with stable CHF (60 with chronic left heart failure and 60 with chronic right heart failure). All patients had pulmonary function testing, including pulmonary function testing at rest and incremental cardiopulmonary exercise testing (CPX). RESULTS: Patients with right heart failure had a significantly lower end-tidal partial pressure of CO2 (PetCO2), higher end-tidal partial pressure of O2 (PetO2) and minute ventilation/CO2 production (VE/VCO2) at rest. Patients with right heart failure had a lower peak PetCO2, and a higher peak dead space volume/tidal volume (VD/VT) ratio, peak PetO2, peak VE/VCO2, and VE/VCO2 slope during exercise. Patients with right heart failure had more changes in ∆PetCO2 and ∆VE/VCO2, from rest to exercise. CONCLUSIONS: Patients with right heart failure had worse pulmonary function at rest and exercise, which was due to severe ventilation/perfusion (V/Q) mismatching, severe ventilation inefficiency, and gas exchange abnormality.

Differences in exercise capacity in patients with chronic left heart failure and chronic right heart failure.

BACKGROUND: Exercise impairment is common in chronic left heart failure and pulmonary arterial hypertension (PAH). Exercise impairment degree is a strong predictor of clinical outcome. Our purpose was to evaluate differences in exercise capacity using cardiopulmonary exercise testing (CPX) in patients with chronic left and right heart failure, and determine which factors were related to exercise impairment. METHODS: 102 patients with class II/III New York Heart Association were involved in the study (41 with chronic left heart failure, 61 with chronic right heart failure secondary to PAH). All patients underwent CPX to evaluate exercise capacity. RESULTS: Patients with right heart failure had significantly lower peak oxygen uptake (VO2), peak VO2/kg ratio, peak oxygen uptake/heart rate (VO2/HR) ratio and increases in oxygen uptake/increase in work rate (ΔVO2/ΔWR) slope, and had higher minute ventilation/CO2 production ratio and peak dead space volume/tidal volume during exercise. In patients with left heart failure, peak VO2/HR ratio was positively correlated with ΔVO2/ΔWR slope. However, VO2 and VO2/HR ratio were positively correlated with ΔVO2/ΔWR slope in patients with right heart failure. CONCLUSIONS: Compared with left heart failure, patients with right heart failure showed worse exercise capacity resulting from worse pulmonary and cardiovascular adaptation to exercise.

Differences in pulmonary function and exercise capacity in patients with idiopathic dilated cardiomyopathy and idiopathic pulmonary arterial hypertension.

OBJECTIVES: We observed the pulmonary function and exercise capacity of idiopathic dilated cardiomyopathy (IDCM) and idiopathic pulmonary arterial hypertension (IPAH) patients using cardiopulmonary exercise testing (CPX). We evaluated and compared the two groups. BACKGROUND: Pulmonary abnormalities and decreased exercise capacity are common in IDCM and IPAH. Little is known about the differences in these two syndromes. METHODS: Sixty-three patients were involved the study, 23 with IDCM and 40 with IPAH. All patients underwent pulmonary function testing at rest and CPX. RESULTS: Patients with IPAH had a higher peak respiratory frequency (32.40 ± 7.88 vs 29.60 ± 6.50 b/min), peak dead space volume/tidal volume (29.33 ± 4.55 vs 26.30  ± 3.31%), peak end-tidal partial pressure of O2 (125.18 ± 5.88 vs 115.17 ± 6.06 mm Hg), peak minute ventilation/CO2 production (50.14 ± 13.26 vs 33.50 ± 6.80 L/min/L/min), and a lower peak oxygen uptake (1262.70 ± 333.34 vs 742.76 ± 194.72 ml/min), peak minute ventilation (38.20 ± 13.07 vs 45.33 ± 12.31 L), peak oxygen uptake/heart rate (5.11 ± 1.47 vs 9.43 ± 2.79 ml/b) and peak end-tidal partial pressure of CO2 (23.73 ± 5.39 vs 35.30 ± 5.45 mm Hg) during exercise. CONCLUSIONS: Compared to IDCM, patients with IPAH had worse pulmonary function and exercise capacity resulting from severe ventilation/perfusion mismatching and gas exchange abnormalities.

[Sarcolemmal sodium-calcium exchanger mediated the beneficial effects of myocardial ischemic preconditioning and pharmacological preconditioning].

OBJECTIVE: To investigate the role of sodium-calcium exchanger (NCX) on ischemic preconditioning and pharmacological preconditioning. METHODS: Cultured rat neonatal cardiomyocytes were randomly divided into 6 groups: (1) ischemia/reperfusion group (9 h ischemia followed by 1 h reperfusion, I/R), (2) ischemic preconditioning group (1.5 h ischemia/1 h reperfusion + I/R), (3) pharmacologic preconditioning group, adenosine (10 micromol/L) pretreated for 1 h + I/R, (4) calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-93 (0.5 micromol/L for 0.5 h) + ischemic preconditioning group, (5) KN-93 + pharmacologic preconditioning group, (6) control group. The leakage of intracellular lactate dehydrogenase (LDH) in various groups was determined by biochemical autoanalyzer. Semi-quantitative RT-PCR was employed to measure the mRNA levels of sodium-calcium exchanger. Activity of sodium-calcium exchanger (Na(+)-dependent (45)Ca(2+) uptake) was measured by liquid scintillation counting. RESULTS: (1) Compared to the I/R group, the LDH leakages in both ischemic preconditioning group and pharmacologic preconditioning group were significantly reduced (P < 0.05) while significantly increased in the KN-93 + pharmacologic preconditioning group and the KN-93 + ischemic preconditioning group (P < 0.05). (2) The Na(+)-dependent (45)Ca(2+) uptake was significantly increased in the I/R group (P < 0.05) compared to control group and this increase could be significantly attenuated in ischemic preconditioning group and adenosine pretreatment group (P < 0.05). (3) The expression of NCX mRNA in I/R group was also significantly increased (P < 0.05) in the I/R group (P < 0.05) compared to control group and this increase could be significantly attenuated in ischemic preconditioning group and adenosine pretreatment group (P < 0.05), CaMKII inhibitor KN-93 significantly abolished these effects in preconditioning group (P < 0.05) and in adenosine pretreated group (P < 0.05). CONCLUSION: NCX mediated the cardioprotective effects of ischemic preconditioning and pharmacological preconditioning in the neonatal cardiomyocytes I/R model.