Sleep apnea and pulmonary hypertension

Summary The pulmonary artery pressure values of 65 patients with sleep apnea syndrome were measured at rest and during ergometer exercise up to 100 W. Pulmonary hypertension at rest was found in 13, and during exercise in 31 more patients. Only 8 patients with pathological pressure findings suffered from pulmonary hypertension in combination with a pulmonary or cardiac disease. In the other 36 patients, no indication of a primary cause of pulmonary hypertension apart from sleep apnea syndrome could be found. Out of the 65 patients, 11 with a finding of more than 20 apnea episodes per hour's sleep underwent polysomnographic recordings in the sleep laboratory. The hemodynamic parameters were continuously measured. All 11 patients had a finding of severe sleep apnea with more than 300 apnea episodes during the night of recording. In 6 patients, the appearance of apnea episodes was accompanied by only moderate changes in pulmonary artery pressure. In 5 patients, there were critical increases in pulmonary artery pressure, which went along with increases in cardiac output and in pulmonary capillary wedge pressure. Increases in pulmonary vascular resistance were established in 3 out of these 5 patients, and a slight decrease in 2. The mechanism of hypoxic vasoconstriction of the pulmonary arteries may account for the pressure increases in 3 of our patients, but fails to explain the findings in the other 2 patients. Nocturnal changes in pulmonary artery pressure in patients with sleep apnea may therefore have different causes. Pulmonary hypertension constitutes a severe complication in patients with sleep apnea. As 55% of all sleep apnea patients were found to suffer from pulmonary hypertension without any indication of a primary pulmonary or cardiac disease, the possibility that pulmonary hypertension results should not be underestimated in patients with suspected sleep apnea syndrome. Measurements of the pulmonary artery pressure must therefore be included in the examination regimen of such patients.Abbreviations ECG electrocardiogram - REM rapid eye movement     

Main Pulmonary Artery Dilatation in Patients with Anthracofibrosis

This study assessed main pulmonary artery diameter of patients with anthracofibrosis. Patients with anthracofibrosis and CT scans were evaluated after exclusion of patients with co-existing disease. We measured the diameter of the main pulmonary artery (PAD) and ascending aorta (AD) and calculated the pulmonary artery to aorta ratio (APR). The upper reference limit for comparison of PAD was 29 mm. Cut-off values for PAD and APR indicating pulmonary hypertension were 33 mm and 1. We correlated the CT parameters with echocardiographic results. Total 51 patients were included in the analysis. The mean PAD, AD, and APR were 33 mm, 38 mm, and 0.87 respectively. The PAD was larger than the upper reference limit, 29 mm (P<0.001). The PAD was >33 mm in 30 (65%) and the APR was >1 in 9 patients (18%). Of 21 patients with echocardiography, 11 (52%) were found to have pulmonary hypertension. There was no statistical difference in the diagnosis of pulmonary hypertension between echocardiography and CT (P=1.000). In conclusion, main pulmonary artery is dilated in patients with anthracofibrosis more than in the healthy population.

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Clinical and haemodynamic evaluation of chronic thromboembolic pulmonary hypertension patients scheduled for pulmonary thromboendarterectomy. Is schistosomiasis hypertension an important confounding factor?

INTRODUCTION:

Chronic thromboembolic pulmonary hypertension is a disease affecting approximately 4,000 people per year in the United States. The incidence rate in Brazil, however, is unknown. The estimated survival for patients with chronic thromboembolic pulmonary hypertension without treatment is approximately three years. Pulmonary thromboendarterectomy for select patients is a potentially curative procedure when correctly applied. In Brazil, the clinical and hemodynamic profiles of chronic thromboembolic pulmonary hypertension patients have yet to be described.

OBJECTIVES:

To evaluate the clinical and hemodynamic characteristics of chronic thromboembolic pulmonary hypertension patients scheduled for pulmonary thromboendarterectomy in a referral center for chronic thromboembolic pulmonary hypertension treatment in Brazil.

METHODS:

From December 2006 to November 2009, patients were evaluated and scheduled for pulmonary thromboendarterectomy. The subjects were classified according to gender, age and functional class and were tested for thrombofilia and brain natriuretic peptide levels.

RESULTS:

Thirty‐five consecutive chronic thromboembolic pulmonary hypertension patients were evaluated. Two patients tested positive for schistosomiasis, and 31 were enrolled in the study (19 female, 12 male). The majority of patients were categorized in functional classes III and IV. Hemodynamic data showed a mean pulmonary vascular resistance (PVR) of 970.8 ± 494.36 dynas·s·cm^‐5 and a low cardiac output of 3.378 ± 1.13 L/min. Linear regression revealed a direct relation between cardiac output and pulmonary vascular resistance. Paradoxical septal movement was strongly correlated with pulmonary vascular resistance and cardiac output (p = 0.001). Brain natriuretic peptide serum levels were elevated in 19 of 27 patients.

CONCLUSIONS:

In a referral center for pulmonary hypertension in Brazil, chronic thromboembolic pulmonary hypertension patients evaluated for pulmonary thromboendarterectomy had a hemodynamically severe status and had elevated brain natriuretic peptide serum levels. There was a predominance of females in our cohort, and the prevalence of hematological disorders and schistosomiasis was low (less than 10%).     

Plasma C-reactive protein and endothelin-1 level in patients with chronic obstructive pulmonary disease and pulmonary hypertension

Pulmonary hypertension is a frequent complication of chronic obstructive pulmonary disease (COPD) and associated with a worse survival and increased risk of hospitalization for exacerbation of COPD. However, little information exists regarding the potential role of systemic inflammation in pulmonary hypertension of COPD. The purpose of the present study was to investigate the degree of C-reactive protein (CRP) and endothelin-1 (ET-1) levels in COPD patient with and without pulmonary hypertension. The levels of CRP and ET-1 were investigated in 58 COPD patient with pulmonary hypertension and 50 patients without pulmonary hypertension. Pulmonary hypertension was defined as a systolic pulmonary artery pressure (Ppa) ≥35 mmHg assessed by Doppler echocardiography. Plasma CRP and ET-1 levels were significantly higher in patients with pulmonary hypertension than in patients without hypertension. There were significant positive correlations between the plasma ET-1 level and CRP level in the whole study groups. For COPD patients, systolic Ppa correlated significantly with plasma CRP levels and plasma ET-1 levels. These findings support a possibility that CRP and ET-1 correlate to pulmonary hypertension in COPD patients.     

Clinical Characteristics and Survival of Korean Idiopathic Pulmonary Arterial Hypertension Patients Based on Vasoreactivity

We aimed to identify a vasoreactive subset of patients with idiopathic pulmonary arterial hypertension (IPAH) in Korea and to show their clinical characteristics and prognosis. Data on patients who were diagnosed with IPAH at Asan Medical Center between January 1994 and March 2013 were retrospectively collected. Acute vasodilator testing was performed with inhaled nitric oxide during diagnostic right heart catheterization. A positive acute response was defined as a reduction in mean pulmonary arterial pressure (PAP) ≥10 mmHg to an absolute level of mean PAP <40 mmHg without a decrease in cardiac output. Among a total of 60 IPAH patients included for analysis, 9 (15%) showed a positive acute response to acute vasodilator testing. Acute responders showed significantly lower peak velocity of a tricuspid regurgitation jet on echocardiography (4.1±0.3 m/s vs. 4.6±0.6 m/s; P=0.01) and significantly lower mean PAP hemodynamically (47±10 mmHg vs. 63±17 mmHg; P=0.003) than non-responders at baseline. The survival rate of acute responders was 88% at 1, 3, 5, and 10 yr, respectively, which was significantly higher than that of non-responders (85%, 71%, 55%, and 40%, respectively; P=0.029). In conclusion, Korean IPAH patients with vasoreactivity showed better baseline hemodynamic features and survival than those without vasoreactivity.

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Open Pulmonary Thromboembolectomy in Patients with Major Pulmonary Thromboembolism

Purpose

We retrospectively analyzed open pulmonary thromboembolectomy in patients with acute and chronic pulmonary thromboembolism.

Materials and Methods

Between August 1990 and May 2005, 12 consecutive patients with acute and chronic pulmonary thromboembolism underwent open pulmonary thromboembolectomy at Yonsei Cardiovascular Center. Their mean age was 47.5 years, and 7 of the patients were female. Among 12 patients, 5 had acute onset, and 7 had chronic disease, and 9 patients were associated with deep venous thrombosis. Extent of pulmonary embolism was massive in 3 patients with hemodynamic instability, and submassive in 8 patients. Preoperative echocardiogram revealed elevated right ventricular pressure in all patients, and 7 patients were in NYHA functional class III or IV. Pulmonary thromboembolectomy was performed in all patients under total circulatory arrest.

Results

There were 2 hospital deaths (16.7%). Among the patients who survived, mean right ventricular pressure was decreased significantly from 64.3 mmHg to 34.0 mmHg with improvement of NYHA functional class.

Conclusion

Open pulmonary thromboembolectomy is thought to be an immediate and definitive treatment for massive pulmonary embolism with optimal results. Even though operative mortality is still high, early diagnosis and immediate surgical intervention in highly selective patients may improve the clinical outcome.     

Acute hypothyroidism has no effect on pulmonary vascular resistance

Summary The effect of acute hypothyroidism on the pulmonary circulation was studied in 9 nonobese athyreotic patients by right heart catheterization at rest and during exercise. The patients were studied while they were hypothyroid 2 weeks after ceasing triiodothyronine treatment and while they were euthyroid on replacement therapy. At rest, pulmonary blood flow [4.0±0.6 l/min vs 5.8±1.0 l/min,p<0.01] and systolic pulmonary artery pressure [18±3 mmHg vs 23±2 mmHg,p<0.01] were lower when the patients were hypothyroid than when they were euthyroid. The mean and diastolic pressures in the pulmonary artery and the pulmonary capillary pressures were not different among the groups. Likewise, thyroid hormone levels had no significant effect on pulmonary vascular resistance [100±25 dyn-s-cm^–5 vs 90±23 dyn-s-cm^–5]. With supine exercise, pulmonary blood flow [10.1±1.6 l/min vs. 13.2±2.0 l/min,p<0.01], mean pulmonary artery pressure [25±6 mmHg vs 30±6 mmHg,p<0.02], and systolic pulmonary artery pressure [36±6 mmHg vs 44±8 mmHg,p<0.01] were lower when the patients were hypothyroid. The diastolic pulmonary artery pressure and the pulmonary capillary pressure were similar in both thyroid states. Again, thyroid deficiency had no effect on pulmonary vascular resistance [81±23 dyn-s-cm^–5 vs 76±24 dyn-s-cm^–5]. The lower systolic pressures in the pulmonary artery seen in hypothyroidism are probably due to the decreased systolic volume load of the pulmonary circulation. The data do not suggest that thyroid hormones play a role in the regulation of pulmonary vascular resistance.Abbreviations PVR pulmonary vascular resistance - PAP_M mean pulmonary artery pressure - PCP_M mean pulmonary capillary pressure - PBF pulmonary blood flow     

经胸超声心动图在肺动脉栓塞诊断中的应用价值

目的:探讨经胸超声心动图(TTE)对肺动脉栓塞(PE)的诊断价值.方法:回顾性分析21例经 CT肺动脉造影检查确诊为 PE患者的经胸超声心动图表现.结果:本组21例,经胸超声心动图大致正常者6例;直接检出主肺动脉及左、右肺动脉近段血栓8例;间接征象提示右心负荷过重15例(包括8例直接检出血栓者),均有右心扩大的表现,其中右室内径(30.7±5.4)mm,右房内径(59.4±6.6)mm.彩色多普勒观察到三尖瓣返流16例,检测其返流速度估测出肺动脉收缩压增高15例,收缩压均高于40 mmHg.结论:经胸超声心动图对中央型肺栓塞具有较高的诊断价值,它可以显示血栓发生的部位.对周围型(肺段及远端分支)肺栓塞虽然不能直接做出诊断,但根据右心扩大、三尖瓣返流及肺动脉高压等间接征象,可为肺动脉栓塞的诊断提供佐证,为临床诊断提供帮助.     

Pulmonary vascular resistance as a potential marker of reactive pulmonary hypertension reduction following sildenafil therapy in patients disqualified from orthotopic heart transplantation

PurposeWe sought to determine the predictors of restoration of heart transplantation (HTx) candidacy in patients with systolic heart failure (HF) and reactive fixed pulmonary hypertension (RFPH) defined as pulmonary vascular resistance (PVR) > 2.5 Wood units (WU), transpulmonary gradient (TPG) > 12 mmHg or ≤2.5 WU with systolic arterial pressure ≤85 mmHg during vasoreactivity test, following sildenafil therapy.Material and methodsBetween 2007 and 2018 1136 patients were evaluated at our department as candidates for HTx. Thirty-five of them, who presented with systolic HF and were not eligible for HTx due to RFPH, were included in the study (31 men aged 55.1 ± 7.4 years). In all the patients sildenafil was introduced and up-titrated to a maximal tolerated dose in addition to optimal medical therapy. Patients were assessed at 3–6 months intervals.ResultsDuring median 11 months (interquartile range 6–18 months) reduction of RFPH enabling qualification for HTx was observed in 62.9% patients. Higher baseline PVR (OR 0.32; 95% CI (0.14–0.74) p < 0.001), pulmonary artery systolic pressure (PASP) (OR 0.94, 95% CI (0.88–0.99) p = 0.05), mean artery pulmonary pressure (mPAP) (OR 0.87, 95% CI (0.77–0.98) p = 0.02) and TPG (OR 082, 95% CI (0.70–0.96) p = 0.003) were negative predictors of RFPH reduction with sildenafil therapy. In multivariable analysis, lower PVR (p = 0.02) was identified as an independent predictor of RFPH reduction following sildenafil therapy.ConclusionSildenafil therapy can support PH reduction in systolic HF patients uneligible for HTx due to RFPH. Lower baseline PVR was identified as an independent predictor of PH reversibility with sildenafil enabling restoration of HTx candidacy.     

携带人端粒酶反转录酶基因脐血间充质干细胞移植治疗肺动脉高压

背景：保护机体肺血管的内皮细胞,是降低肺循环压力,预防肺动脉高压的重要环节。 目的：观察携带人端粒酶反转录酶基因的脐血间充质干细胞移植对大鼠肺动脉高压的治疗作用。 方法：体外进行脐血间充质干细胞的培养及纯化,在腺病毒介导下使人端粒酶反转录酶基因成功导入脐血间充质干细胞。将60只SD大鼠随机分成3组：肺动脉高压组、空腺病毒组、腺病毒转染组,每组20只,腹腔注射野百合碱进行肺动脉高压模型复制后,于颈内静脉分别注射1 mL的伊戈尔低糖培养基(L-DBEB),1 mL (1.5×1010 L-1)脐血间充质干细胞悬液,1 mL(1.5×1010 L-1)腺病毒介导下人端粒酶反转录酶基因转染的脐血间充质干细胞悬液。移植21 d后检测各组大鼠血流动力学水平、血浆内皮素1水平以及右心室的肥大指数。 结果与结论：各组大鼠动脉血压差异无显著性意义(P > 0.05);与肺动脉高压组及空腺病毒组比较,腺病毒转染组大鼠肺动脉收缩期压力、平均肺动脉压均降低,差异有显著性意义(P < 0.05);腺病毒转染组大鼠右心室肥大指数与肺动脉高压组及空腺病毒组相比较,差异均无显著性意义(P > 0.05);腺病毒转染组大鼠血浆内皮素1水平明显低于肺动脉高压组及空腺病毒组,差异有显著性意义(P < 0.05)。结果表明携带人端粒酶反转录酶基因的脐血间充质干细胞移植后,能够改善大鼠机体血流动力学异常状态,还可以保护机体血管内皮细胞。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

Mental stress increases right heart afterload in severe pulmonary hypertension.

Little is known about mental stress effects on the pulmonary circulation in health and disease. The current study was conducted to investigate whether pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) would further increase during standardized mental stress testing in patients with severe pulmonary hypertension. The study was a prospective analysis of seven patients (average age: 40 years, range from 21 to 56 years) with severe pulmonary hypertension (primary: n = 4, secondary forms: n = 3; resting mean pulmonary artery pressure ranged between 48 and 65 mmHg). Right heart catheterization for the determination of PAP, pulmonary capillary wedge pressure (PCW) and cardiac output (CO) was clinically indicated (diagnostic workup, acute drug testing). Patients accomplished a standardized 10 min mental stress test (computer based, adaptive complex reaction-time task). Pulmonary haemodynamics during stress were compared to resting baseline. During mental stress mean PAP (+/- SEM) increased by 9.4 +/- 2.1 mmHg (P < 0.005). Pulmonary vascular resistance increased by 149 +/- 25 dyne s cm-5 (P < 0.001). Stroke volume decreased by 6.6 +/- 2.2 ml (P < 0.03). The data show that moderate mental stress increases right heart afterload in patients with severe pulmonary hypertension owing to elevation of PVR.     

Pulmonary artery pressure in sleep apnoea and snoring

SUMMARY  There is a renewed interest in pulmonary hypertension (PH) complicating obstructive sleep apnoea (OSA). The prevalence of PH in populations of patients with less severe OSA was documented to be around 10%. The most recent data from both catheterization and echocardiographic studies indicate that as many as 40% of patients with OSA have PH. It has been shown that non-obese patients with normal respiratory function tests can develop pulmonary hypertension. One of the other possible mechanisms involved may be the presence of heightened pulmonary artery pressure response to hypoxia. There are now data available to indicate that treatment with nasal CPAP can decrease or even normalize pulmonary artery pressure in patients with sleep apnoea.     

Präkapilläre pulmonale Hypertonie

Precapillary pulmonary hypertension (PH) is defined by hemodynamic variables (i.e., a mean pulmonary artery pressure ≥?25 mmHg in the presence of normal pulmonary capillary wedge pressure). The relationship between PH and sleep-disordered breathing is more complex than initially thought. Earlier studies have shown that obstructive sleep apnea (OSA) can induce chronic daytime PH. It has only recently been recognized that OSA is frequently associated with acute PH in the setting of pulmonary embolism and that chronic PH can lead to the development of central sleep apnea/Cheyne–Stokes respiration.     

Perioperative blood pressure control in hypertensive and normotensive patients undergoing off-pump coronary artery bypass grafting: prospective study of current anesthesia practice

Aim

To analyze blood pressure changes during intra- and immediate postoperative period in patients undergoing off-pump coronary artery bypass grafting.

Methods

The study included 355 consecutive patients undergoing off-pump coronary artery bypass grafting between January 5, 2004 and December 30, 2005. Out of these patients, 325 were allocated into groups with preoperative history of hypertension (n = 115) and without preoperative history of hypertension (n = 210). Systolic, diastolic, and mean arterial blood pressure was measured at the following four time points: on the day before surgery, before anesthesia induction, after the last graft, and on entry to intensive care unit.

Results

Mean arterial pressure was significantly higher in patients with a history of hypertension on the day before surgery (97 vs 92 mm Hg, P = 0.003, Mann-Whitney test) and before anesthesia induction (107 vs 98 mm Hg; P = 0.003). It was higher at all measuring points (after the last graft, 79 vs 78 mm Hg; and on entry to intensive care unit, 88 vs 86 mm Hg), but this difference was neither statistically nor clinically significant. The study showed that mean arterial pressure followed similar dynamics over time in both patient groups (P<0.001 both), with no significant time-dependent between-group differences.

Conclusion

Current anesthesia techniques that include deep opioid analgesia in combination with vasodilators provide a satisfactory control of intraoperative hypertension. Management of blood pressure changes during intra- and immediate postoperative period in off-pump coronary artery bypass grafting patients with preoperative hypertension was no more difficult than in patients without preoperative hypertension.Monitoring of hemodynamic stability, especially blood pressure and heart rate during perioperative period, is an important consideration (1). During conventional open heart surgery, hypertension can occur at almost any time, ie before, during, or after surgery, and is most commonly mediated by an increase in sympathetic tone.Off-pump coronary artery bypass grafting is a procedure that may achieve better in-hospital outcome, including shorter length of stay (2,3). Hypertension associated with off-pump coronary artery bypass grafting is typically not a result of dramatic increase in systemic vascular resistance (4).The reported incidence of perioperative hypertension associated with conventional coronary artery bypass grafting (CABG) ranges from 30 to 80%, and this wide range may explain different definitions of the condition and preoperative comorbid states (5).To the best of our knowledge, there are no studies dealing with off-pump coronary artery bypass grafting. The aim of our study was to analyze perioperative hypertensive response in patients undergoing off-pump coronary artery bypass grafting. We hypothesized that it was more difficult to control perioperative hypertension in these patients who had been preoperatively hypertensive than in those who had not.     

Accuracy of Doppler echocardiography in the hemodynamic assessment of pulmonary circulation in patients with systemic sclerosis

PurposePulmonary hypertension (PH) is an ominous complication in systemic sclerosis patients (SSc) and echocardiography is a screening tool for its detection. The goal of this study was to assess the reliability of resting and exercise echo Doppler parameters with data obtained by right heart catheterization (RHC).Material and methodsWe included 91 patients (84 F, 53.3 ± 15.2 years) with SSc. Transthoracic echocardiography followed by exercise Doppler-echocardiography (EDE) were performed. A positive EDE was defined as a ≥20 mmHg increase in tricuspid regurgitation peak gradient (TRPG). RHC with exercise was performed in positive EDE patients and/or in subjects with resting TRPG > 31 mmHg.ResultsFinally, RHC was performed in 20 patients. The correlation for the echocardiography and invasive measurement of systolic (sPAP) and mean (mPAP) pulmonary artery pressure was r = 0.66 (p = 0.001) and r = 0.7 (p = 0.001), respectively. We also found significant correlation between echocardiography and invasive measurement of exercise sPAP r = 0.68 (p = 0.001) and exercise mPAP r = 0.67 (p = 0.002). There was a correlation between pulmonary vascular resistance (PVR) assessed by echocardiography and measured by RHC r = 0.49, p = 0.027. The equation derived within our population was: PVR by echocardiography = 9.6*TRV/TVI_RVOT+0.068. We also performed ROC analysis to predict PVR > 2 WU. Our results highlight that sPAP has the highest AUC (0.802, 95% CI 0.585–1).ConclusionDoppler resting and exercise echocardiography may provide a reliable, noninvasive method for determining resting and exercise sPAP, mPAP, and PVR in SSc patients, although it may underestimate or overestimate these values in some individuals. Doppler echocardiography does not replace RHC for definite hemodynamic assessment of suspected PH.     

Pulmonary hypertensive necrotizing arteritis: An unusual case of unilateral involvement in an infant with congenital heart disease

Pulmonary hypertension is clinically defined as a pulmonary arterial pressure greater than 25 mmHg at rest or greater than 30 mmHg during exercise. We report a unique case of an infant with congenital heart disease causing pulmonary hypertension and necrotizing pulmonary arteritis but affecting only one lung. In conclusion, in pulmonary valve atresia, the lungs may be supplied via aortopulmonary collaterals. Necrotizing pulmonary arteritis is a severe lesion seen in irreversible pulmonary hypertension.     

Histologic changes of pulmonary arteries in congenital heart disease with left-to-right shunt (part 1): correlated with preoperative pulmonary hemodynamics. Emphasizing the significance of pulmonary arterial concentration

The hemodynamic findings related to the histologic changes in the small pulmonary arteries in congenital heart disease were analyzed with a left-to-right shunt. A lung biopsy was performed during the repair because of pulmonary arterial (PA) hypertension (mean PA pressure > or = 15 mmHg) in 38 patients. There were 13 patients whose age ranged from 2 years to 25 years old. A preoperative cardiac catheterization was performed to locate the site of the defect and to determine the preoperative hemodynamic findings. Among them, 29 patients had pulmonary vascular resistance (PVR) > 2.5 unit/m2. The lung biopsy specimens were investigated microscopically for the Heath- Edward grade, morphometric analysis of medial wall thickness (MWT) and the rate of the decrease in the pulmonary arteriolar concentration (PAC) obtained by the alvoelo-arterial ratio divided by patients' age. All patients were in the Heath-Edward grade I to III (29 patients in grade I). This grade correlated with the MWT, but did not correlate with a decrease in the PAC. The MWT and the rate of the decrease in the PAC did not accompany each other, but either one had the tendency dominate the pattern in individual patients. The MWT had a close correlation with the mean PA pressure and PVR, and an even closer correlation in patients with a high PVR and those older than 2 years of age. The rate of the decreased in the PAC showed a weak correlation with the shunt volume in patients over 2 years of age or with a large shunt. In the high flow group (PVR < 2.5 unit/m(2), Qp/Qs > 2.0, n=14) the MWT was significantly thinner and the rate of the decrease in the PAC was significantly higher than the high resistance group (PVR > 2.5 unit/m2, Qp/Qs2 < 2.0, n=13). The rate of the decrease in the PAC correlated with the patients' age, but the MWT did not. The lung biopsy results in patients who had both left-to-right shunts and pulmonary hypertension showed that the rate of the decrease in the PAC was weakly related to the shunt volume and the MWT was related to the PA pressure and PVR. Either an increased MWT or the rate of the decrease in the PAC tended to dominate. These phenomena were prominent in patients older than 2 in whom a wide range of individual variations were noted in the morphometric pattern. The medial hypertrophy and the rate of the decrease in the PAC may be induced by different stimuli or that medial hypertrophy may play a role in preventing PAC decrease.     

A single open sea air dive increases pulmonary artery pressure and reduces right ventricular function in professional divers

After decompression from dives, bubbles are frequently observed in the right ventricular outflow tract and may lead to vascular damage, pulmonary arterial hypertension and right ventricular overload. No data exist on the effect of open sea diving on the pulmonary artery pressure (PAP). Eight professional divers performed an open sea air dive to 30 msw. Before and postdive a Doppler echocardiographic study was undertaken. Systolic pulmonary artery pressure (SPAP) was estimated from measurement of peak flow velocity of the tricuspid regurgitant jet; the ratio between pulmonary artery acceleration times (AccT) and right ventricular ejection time (RVET) was used as an estimate of the mean PAP. No evidence of either patent foramen ovale or intra-pulmonary shunt was found in any subject postdive after performing a Valsalva maneuver. SPAP increased from 25 ± 3 to 33 ± 2 mmHg and AccT/RVET ratio decreased from 0.44 ± 0.04 to 0.3 ± 0.02 20 min after the dive, respectively. Pulmonary vascular resistance increased from 1.2 ± 0.1 to 1.4 ± 0.1 Woods Units. Postdive right ventricle end-diastolic and end-systolic volumes were increased for about 19% (P = 0.001) and 33% (P = 0.001) and right ejection fraction decreased about for 6% (P = 0.001). Cardiac output decreased from 4.8 ± 0.9 (l min⁻¹) to 4.0 ± 0.6 at 40 min postdive due to decreases in heart rate and stroke volume. This study shows that a single open sea dive may be associated with right heart overload due to increased pressure in the pulmonary artery.     

Association between left ventricular diastolic dysfunction and severity of chronic obstructive pulmonary disease

OBJECTIVES:

The prevalence of electrocardiographic and echocardiographic abnormalities in chronic obstructive pulmonary disease according to disease severity has not yet been established. The aim of this study was to assess the prevalence of electrocardiographic and echocardiographic abnormalities in chronic obstructive pulmonary disease patients according to disease severity.

METHODS:

The study included 25 mild/moderate chronic obstructive pulmonary disease patients and 25 severe/very severe chronic obstructive pulmonary disease patients. All participants underwent clinical evaluation, spirometry and electrocardiography/echocardiography.

RESULTS:

Electrocardiography and echocardiography showed Q-wave alterations and segmental contractility in five (10%) patients. The most frequent echocardiographic finding was mild left diastolic dysfunction (88%), independent of chronic obstructive pulmonary disease stage. The proportion of right ventricular overload (p<0.05) and blockage of the anterosuperior division of the left bundle branch were higher in patients with greater obstruction. In an echocardiographic analysis, mild/moderate chronic obstructive pulmonary disease patients showed more abnormalities in segmental contractility (p<0.05), whereas severe/very severe chronic obstructive pulmonary disease patients showed a higher prevalence of right ventricular overload (p<0.05), increased right cardiac chamber (p<0.05) and higher values of E-wave deceleration time (p<0.05). Age, sex, systemic arterial hypertension, C-reactive protein and disease were included as independent variables in a multiple linear regression; only disease severity was predictive of the E-wave deceleration time [r² = 0.26, p = 0.01].

CONCLUSION:

Chronic obstructive pulmonary disease patients have a high prevalence of left ventricular diastolic dysfunction, which is associated with disease severity. Because of this association, it is important to exclude decompensated heart failure during chronic obstructive pulmonary disease exacerbation.     

Effect of nocturnal hypoxia on pulmonary hemodynamics in patients with obstructive sleep apnea

Effects of apnoea induced nocturnal hypoxia on pulmonary haemodynamics (PH) in pts with OSA are still under debate. We studied PH in 67 pts (64 M and 3 F) mean +/- SD: age 45 +/- 8 years, with severe OSA, AHI 62 +/- 22. Patients had normal spirometry: FVC 98 +/- 15% N, FEV1 97 +/- 16% N and arterial blood gases--PaO2 72 +/- 10 mmHg, PaCO2 40 +/- 4 mmHg. PH were studied using Swan-Ganz thermodilution catheter. PH were within normal range: right atrial pressure 4.2 +/- 2.7 mmHg, right ventricular systolic/enddiastolic pressure 28.1 +/- 7.1/5.0 +/- 3.3 mmHg, mean pulmonary artery pressure (PAP) 15.8 +/- 4.6 mmHg, mean pulmonary wedge pressure (PW) 6.8 +/- 3.1 mmHg, cardiac output (CO) 5.6 +/- 2.2 L/min. and pulmonary vascular resistance (PVR) 150 +/- 83 dyn.sec.cm-5. During exercise (44 pts) PAP rose from 15.8 +/- 4.3 to 29.8 +/- 9.4 mmHg, PW rose from 6.8 +/- 3.2 to 12.6 +/- 6.8 mmHg and CO from 4.9 +/- 1.9 to 9.2 +/- 4.2 L/min. All patients presented with nocturnal desaturations. Mean oxygen saturation (SaO2 mean) was: 87.4 +/- 5.4%, minimal saturation (SaO2 min) was 57.4 +/- 15.9%. Time spent in desaturation SaO2 < 90% (T90) was 50.7 +/- 26.5%. Results of PH investigations were related to results of pulse oximetry. Linear regression analysis showed week negative correlations between SaO2 mean and: PAP (r = -0.37 p = 0.003), PVR (r = -0.37 p = 0.007), and positive correlation between T90 and PAP (r = 0.37 p = 0.008). We conclude that there is no diurnal pulmonary hypertension at rest in patients with severe OSA and normal lung function even in the presence of severe overnight nocturnal desaturations. In half of studied patients we observed pulmonary hypertension during exercise.