Effect of Acute Hyperoxia and Hypoxia on the Central Blood Volume in Patients with Chronic Pulmonary Diseases

To investigate whether the central blood volume (CBV) reflects the pulmonary vasculature, we measured CBV before and after the inhalation of 100 % or 13 %O2 for 15 min in patients with chronic pulmonary diseases. Using the Stewart-Hamilton technique, we measured CBV using a lung water computer, employing sodium as an indicator. Thirteen patients inhaled 100 % O2, while 8 patients breathed 13 % O2. Hyperoxia increased CBV significantly and the delta change in CBV(△CBV)correlated significantly with the change in total pulmonary resistance index(△TPPI;r=-0.65, p<0.02),the change in mixed venous oxygen tension(△PvO2; r = - 0.58, p < 0.05) and the change in the coefficient of oxygen delivery (△COD;r=0.71, p<0.02). Hypoxic breathing caused little or no change in CBV, but △CBV correlated well with△TPRI(r=-0.74, p<0.05)and△PvO2 (r=0.85,p<0.01)。 Our results suggest that△CBV provides a good index of the pulmonary vascular bed, on which efficient gas-exchange occurs

Ventilatory and Pulmonary Vascular Responses to Acute Hypoxia in Patients with Chronic Obstructive Lung Disease

The present study was undertaken to examine the pulmonary vascular and ventilatory responses to acute hypoxia in chronic obstructive lung disease. Pulmonary hemodynamics, minute ventilation (VE) and oxygen uptake (VO2) were serially measured during inhalation of 13 %O2 for 15 min. There was a wide variablility in the pulmonary, vascular response to acute hypoxia. ,The initial increase in VE and the magnitude of change in VO2 were significantly lower in subjects developing a 25 % or great increase in mean pulmonary arterial pressure during hypoxic breathing. These results suggest that the ventilatory response to acute hypoxia plays a significant role in the pulmonary vascular response to acute hypoxia, and blunted initial ventilatory response to acute hypoxia may be a physiological adaptation to enhanced responses of pulmonary vessels

Progressive Retrograde Acute Coronary Occlusion after Gianturco-Roubin Stenting

We report a case of progressive retrograde acute coronary occlusion after Gianturco-Roubin (GR) stenting in a patient with two vessel diseases. A GR stent was implanted in the proximal part of the left anterior descending artery (LAD) because of suboptimal results of percutaneous transluminal coronary angioplasty (PTCA). More than 90% stenosis occurred in the non-stented region just distal to the edge of the GR stent. Another stenosis ensued mid-stent after PTCA was performed for that lesion. Acute occlusion from the mid- LAD to the main trunk progressed immediately after PTCA for the LAD. The patient died of cardiogenic shock despite repeated bail-out PTCA procedures for both the main trunk and the proximal LAD. Acute retrograde occlusion might be caused by in-stent thrombosis, or acute recoil of GR stent associated with insufficient stent dilatation and acute coronary arterial elastic recoil

Initial Cardiopulmonary Response to Exercise in Chronic Obstructive Pulmonary Diseases (COPD)

The present study was undertaken to assess the cardiopulmonary response during the initial period of exercise at a low workload in 8 patients with COPD and 10 normal subjects. In the patients with COPD VO2/VE and VCO2/VE were significantly lower than in the normal controls, and more markedly so during the initial period of exercise. SaO2 and Sv O2 decreased dramatically in the initial period of exercise in the COPD compared with the normal subjects. In contrast to the normal subjects, pulmonary artery mean pressure (PAMP) increased substantially during the initial period of exercise in the patients with COPD. These findings imply that blood gas changes on exercise can be explained by the differences in the relative increase of VO2, VCO2, VE and cardiac output. Our study also suggests that the measurement of VO2/VE, VCO2/VE and SvO2 and PAMP on exercise at a low workload, especially during the initial period, may be useful for evaluating the cardiopulmonary response to COPD patients

Successful Resuscitation from Ventricular Fibrillation during Jogging in a Young Patient with Hypertrophic Cardiomyopathy

A 15-year-old girl, who was previously in good health, suddenly collapsed while jogging. Immediate cardiopulmonary resuscitation (CPR) was initiated, and she arrived at our hospital 13 minutes later. The ventricular fibrillation (VF) on admission was reverted to sinus rhythm 18 minutes after collapse by the second cardioversion. The echocardiogram revealed hypertrophic nonobstructed cardiomyopathy (HNOCM), although the 24hr ambulatory electrocardiographic, electrophysiologic and exercise stress tests could not define the exact cause of VF. Exercise-induced ischemia with sustained mild hypokalemia was suspected to be the cause of VF. The patient recovered consciousness three days after admission, and followed an uneventful course of treatment with oral atenolol not associating with disabling neurological deficit. Immediate basic life support and delivery of automatic external defibrillator on the spot is needed to rescue patients with out-of-hospital cardiac arrest

Evaluation of Right Ventricular overload by ^<123>I-MIBG, ^<123>I-BMIPP , and ^<99m>Tc-MIBI

It is important to evaluate the severity of right ventricular (RV) overload in patients with chronic pulmonary diseases or pulmonary thromboembolism because their prognosis depend on the severity of RV overload. Various examination methods have been used to non-invasively evaluate the severity of RV overload. We evaluated the usefulness of recently developed novel radiopharmaceuticals 123I-MIBG, 123I-BMIPP, and 99mTc-MIBI) in patients with chronic respiratory diseases or pulmonary thromboembolism. Myocardial scintigraphy using 1231-MIBG revealed that the ratio of scintillation counts in the interventricular septum (IVS) to those in the left ventricle (LV) correlated negatively with the mean pulmonary arterial pressure (MPAP), suggesting the presence of sympathetic neuropathy due to RV overload. Myocardial scintigraphy using 123I-BMIPP revealed that the ratio of scintillation counts in the RV to those in LV (RV/LV uptake ratio) correlated with MPAP. There was a negative correlation between RV metabolic index [RVMI = (RV/LV ratio of 123I-BMIPP uptake)(RV/LV ratio of 201T1 uptake)] and MPAP. These findings suggested the presence of RV overload-induced fatty acid metabolic disorder. 99iTc-MIBI allows the simultaneous performance of both cardiac pool scintigraphy and myocardial single photon emission computed tomography. RV/LV ratio of 99Tc-MIBI uptake correlated with MPAP. Moreover, RV ejection fraction (RVEF) obtained by right cardiac pool scintigraphy correlated with the RVEF determined by the thermodilution method, suggesting the usefulness of 99mTc-MIBI. Our findings suggest that these radiopharmaceuticals are useful for evaluating the severity of RV overload in patients with chronic respiratory diseases or pulmonary thromboembolism, as well as for evaluating RV overloadinduced metabolic disorders

A Case of Anomalous Origin of the Right Coronary Artery from the Left Sinus of Valsalva - Special Reference to PTCA Procedures and Aspirin Effect to Failed PTCA of the Anomalous Coronary Artery -

An unusual case of a 53-year-old male with a right coronary artery originating from the left sinus of Valsalva is presented. Despite acute myocardial infarction due to occlusion of the aberrant right coronary artery (RCA), PTCA was not immediately performed. After 81 mg/day of aspirin had been administered for 1 month, PTCA to the subtotal stenosis of the RCA resulted in failure due to poor deployment of the guiding catheters complicated by withdrawal and uncrossing of a guiding wire. However, complete recanalization occurred after giving the patient 162 mg/day of aspirin for 8 months. Low dose aspirin was effective in recanalizing the subtotal stenosis after failed PTCA

Pulmonary Hypertension in a Patient with Essential Thrombocythemia

A 67-year-old woman with essential thrombocythemia (ET) developed acute heart failure and marked pulmonary hypertension (PH). No clear cause for the PH could be initially found. We suspected that thrombocytosis might cause PH. Treatments with anticoagulant (heparin and warfarin), platelet- lowering (hydroxyurea), and antiplatelet (ticlopidine) agents resulted in improvement of the clinical, hemodynamic conditions, and the control of platelet counts. We found that the main etiology of PH in the present case might be the pulmonary capillary obstruction from local pulmonary microthrombosis complicated with ET. Although PH associated with ET is uncommon, it should be always considered as a possible cause of dyspnea in patients with ET

Adrenomedullin is not Related to Acute Hypoxic Pulmonary Vascular Response in Patients with Chronic Respiratory Disease

In the present study, acute hypoxia was induced in 19 patients with chronic respiratory disease to evaluate the corre lation between pulmonary circulation kinetics and adrenomedullin (AM) levels. Using radioimmunoassay (RIA), pulmonary circulation kinetics were evaluated before and after hypoxic loading (13% oxygen for 15 minutes) by determining AM levels in plasma obtained from the pulmonary artery (PA) and the right femoral artery (FA). There were no significant differences in pre-hypoxia plasma AM levels between samples obtained from the PA and FA, and plasma AM levels did not change after hypoxic loading. Subjects were classified into two groups [responders (R) and non-responders (NR) ] to evaluate changes in the mean pulmonary arterial pressure(笆ｳMPAP). There were no changes in AM levels between these two groups in either the PA or FA after hypoxic loading. These results suggest that AM do not appear to be related to hypoxic pulmonary vascular response to acute hypoxic loading in patients with chronic respiratory disease

Decreasing the Pressure Gradient of the Left Ventricular Outflow Tract by Single-lead VDD Pacing in a Patient with Hypertrophic Obstructive Cardiomyopathy

A 59-year-old woman with hypertrophic cardiomyopathy of 8 years duration, who had been taking ﾎｲ-blocker, was admitted to our hospital for exertional dyspnea and previous syncope. Cardiac catheterization showed a prominent left-ventricular outflow tract (LVOT) pressure gradient, and hypertrophic obstructive cardiomyopathy (HOCM) was diagnosed. To reduce LVOT obstruction, we implanted a single-lead VDD-mode pacemaker. Cardiac catheterization after the implantation revealed a remarkable decrease in the LVOT pressure gradient with short atrioventricular delay, 80 msec, and her symptoms disappeared. A singlelead VDD pacemaker is also a useful treatment for an HOCM patient due to the relative ease with which it can be implanted