Fit for Duty: Lessons Learned from Outpatient and Homebound Hematopoietic Cell Transplantation to Prepare Family Caregivers for Home-Based Care

In the past decade, the demand for home-based care has been amplified by the Coronavirus disease 2019 pandemic. Home-based care has significant benefits for patients, their families, and healthcare systems, but it relies on the often-invisible workforce of family and friend caregivers who shoulder essential health care responsibilities, frequently with inadequate training and support. Hematopoietic cell transplantation (HCT), a potentially curative but intensive treatment for many patients with blood disorders, is being increasingly offered in home-based care settings and necessitates the involvement of family caregivers for significant patient care responsibilities. However, guidelines for supporting and preparing HCT caregivers to effectively care for their loved ones at home have not yet been established. Here, informed by the literature and our collective experience as clinicians and researchers who care for diverse patients with hematologic malignancies undergoing HCT, we provide considerations and recommendations to better support and prepare family caregivers in home-based HCT and, by extension, family caregivers supporting patients with other serious illnesses at home. We suggest tangible ways to screen family caregivers for distress and care delivery challenges, educate and train them to prepare for their caregiving role, and create an infrastructure of support for family caregivers within this emerging care delivery model.

Grandparents of children with cancer: a controlled comparison of perceived family functioning

PURPOSE

Grandparents can be profoundly emotionally affected when a grandchild is diagnosed with cancer. They also often provide invaluable support for the family (e.g., caring for the sick child and/or siblings). Multigenerational family functioning may therefore change. Limited research has assessed grandparents' perspectives after their grandchild is diagnosed with cancer. In this study, we aimed to (1) assess differences in perceived family functioning among grandparents of a child with cancer and grandparents of healthy children and (2) assess the cancer-specific and demographic factors related to perceived family functioning in grandparents of a grandchild with cancer.

PROCEDURE

Grandparents of a child with cancer (n = 89) and grandparents of healthy children (n = 133) completed the general functioning, communication, and problem-solving scales of the Family Assessment Device. We used multilevel models with a random intercept to detect (1) between-group differences and (2) identify factors related to perceived family functioning among grandparents with a grandchild with cancer.

RESULTS

Grandparents with a grandchild with cancer reported poorer family functioning than grandparents with healthy grandchildren. Among the grandparents with a grandchild with cancer, impairments in family functioning were correlated with fewer years since diagnosis, providing care to their sick grandchild and/or siblings and living far away from the sick grandchild.

CONCLUSIONS

The detrimental impact of childhood cancer likely extends beyond the immediate family members. Including grandparents in interventions-beginning at diagnosis-to reduce distress and increase cohesion for families of a child with cancer is warranted, particularly for grandparents who provide care to their sick grandchild or siblings.

The perceived influence of childhood cancer on the parents' relationship

OBJECTIVE

When a child is diagnosed with cancer, parents are faced with many practical and emotional challenges that can significantly affect their relationship. This study explores how having a child with cancer affects the quality of the parents' relationship, categorizes time points and events during the child's treatment when the relationship becomes most stressed and/or strengthened, identifies factors that help couples remain emotionally engaged throughout their child's cancer treatment, and assesses parental interest in a counseling intervention.

METHODS

This is a cross-sectional, multicenter study conducted via a semistructured self-administered questionnaire that included the Revised Dyadic Adjustment Scale.

RESULTS

One hundred ninety-two parents of children diagnosed between the ages of 1 and 21 participated. Forty percent felt their relationship moved in a negative direction. Diagnosis and relapse of disease were cited as the most individually stressful time points in the disease trajectory, with hospitalizations and relapse being most stressful on the relationship. Participants felt most emotionally connected at diagnosis and least emotionally connected at the start and end of treatment. The majority of couples indicated interest in counseling to address ways to support their relationship. Soon after diagnosis and during treatment was reported as the preferred time to offer these interventions.

CONCLUSION

This study identified specific events and parent behaviors that strain the couples' relationship during the childhood cancer trajectory. This information can inform the development of a couple's intervention. Prospective research is needed to better understand how childhood cancer affects caregivers' partnerships through survivorship and beyond.

Is Participating in Psychological Research a Benefit, Burden, or Both for Medically Ill Youth and Their Caregivers?

Few data exist pertaining to the perceived burdens or benefits of medically ill children participating in psychological research studies, particularly in outpatient pediatric settings. As part of a larger study that involved completing self-report questionnaires, this study assessed whether participation was burdensome and/or beneficial to 271 children undergoing treatment for cancer, NF1, sickle cell, HIV, primary immune deficiencies, and Li Fraumeni and to their caregivers. The majority of patients (83%) and their caregivers (93%) did not find participating burdensome. Moreover, the majority of patients (85%) and caregivers (95%) found at least some benefit to participation, including finding it helpful to be asked about issues that affect their life and feeling good about helping others. The data suggest that resistance to psychological research based on the belief that such research is intrusive and potentially harmful overestimates the negative aspects and potentially impedes progress studying positive psychosocial outcomes in outpatient pediatric research.

The HIV-infected child: parental responses and psychosocial implications

Four dimensions of psychological adaptation of 101 parents of HIV-infected children were examined. Heightened anxiety, depression, and anticipatory grief were associated with child's age at diagnosis, parent's HIV status, and parent's relationship to the child. Parents at higher risk for psychological distress were identified, and an optimum time point for intervention is suggested.

Tomorrow's survivors: siblings of human immunodeficiency virus-infected children

There has been no empirical research on the psychologic effects on siblings of children afflicted with human immunodeficiency virus (HIV). This article therefore draws from existing sources: the literature of siblings of children with other chronic illnesses and the clinical experiences of those working with HIV-infected children and their siblings. Topics covered include secrecy and communication within the family, the parent-child relationship, the sibling relationship, school issues, the impact of parental mourning on siblings, the sibling's mourning, and recommendations for future research. The goals of this review are to alert researchers to issues that need to be addressed, and to inform the development of interventions for siblings.

The development of a Q-sort behavioral rating procedure for pediatric HIV patients

Developed a Q-sort procedure to assess social, emotional, and motivational behavior associated with central nervous system disease among 180 HIV-infected pediatric patients. These ratings were factor analyzed and scales were derived based on the factor structure. Younger (M age = 1.03 years) patients with HIV-associated encephalopathy were rated as more apathetic and nonsocial in their behavior than nonencephalopathic younger patients. Older (M age = 7.8 years) encephalopathic patients had significantly higher scores on scales measuring depression, autism, and irritability compared to nonencephalopathic patients from this age group. A subgroup (26 patients) showed a significant decrease in these elevated scores after a 6-month course of AZT.

Pneumocystis carinii pneumonia (PCP) and your child: a parent information booklet

A parent education booklet describing Pneumocystis carinii pneumonia (PCP) was prepared by the Pediatric Branch of the National Cancer Institute. In addition to information about prophylaxis and treatment of PCP, the booklet discusses overall care of children infected with human immunodeficiency virus.

Protein binding sites on Escherichia coli 16S ribosomal RNA; RNA regions that are protected by proteins S7, S9 and S19, and by proteins S8, S15 and S17

Selected groups of isolated 14C-labelled proteins from E. coli 30S ribosomal subunits were reconstituted with 32P-labelled 16S RNA, and the reconstituted complexes were partially digested with ribonuclease A. RNA fragments protected by the proteins were separated by gel electrophoresis and subjected to sequence analysis. Complexes containing proteins S7 and S19 protected an RNA region comprising helices 29 to 32, part of helix 41, and helices 42 and 43 of the 16S RNA secondary structure. Addition of protein S9 had no effect. When compared with previous data for proteins S7, S9, S14 and S19, these results suggest that S14 interacts with helix 33, and that S9 and S14 together interact with the loop-end of helix 41. Complexes containing proteins S8, S15 and S17 protected helices 7 to 10 as well as the "S8-S15 binding site" (helices 20, 22 and parts of helices 21 and 23). When protein S15 was omitted, S8 and S18 showed protection of part of helix 44 in addition to the latter regions. The results are discussed in terms of our model for the detailed arrangement of proteins and RNA in the 30S subunit.

Protein binding sites on Escherichia coli 16S RNA; RNA regions that are protected by proteins S7, S14 and S19 in the presence or absence of protein S9

14C-labelled proteins from E. coli 30S ribosomal subunits were isolated by HPLC, and selected groups of these proteins were reconstituted with 32P-labelled 16S RNA. The isolated reconstituted particles were partially digested with ribonuclease A, and the RNA fragments protected by the proteins were separated by gel electrophoresis and subjected to sequence analysis. Protein S7 alone gave no protected fragments, but S7 together with S14 and S19 protected an RNA region comprising the sequences 936-965, 972-1030, 1208-1262 and 1285-1379 of the 16S RNA. Addition of increasing amounts of protein S9 to the S7/S14/S19 particle resulted in a parallel increase in the protection of the hairpin loop between bases 1262 and 1285. The results are discussed in terms of the three-dimensional folding of 16S RNA in the 30S subunit.

Sarcoma metastatic to the central nervous system parenchyma: a review of the literature

Sarcoma metastatic to cerebral parenchyma, although rare, occurs more frequently than generally recognized. With increased duration of survival due to multi-modal therapy, more CNS metastases are being found. A literature search occasioned by a patient with metastatic sarcoma has produced some interesting results.

Beneficial effects of ibuprofen in pacing-induced myocardial ischemia

Lysosomal membrane instability and platelet activation are both associated with acute myocardial ischemia. The effect of ibuprofen on cathepsin D as a marker of lysosomal membrane "leakiness" and thromboxane B2 as a marker of platelet activation was evaluated in 44 patients with angina pectoris. Samples of blood analyzed for cathepsin D, thromboxane B2, and lactate were withdrawn from the coronary sinus and brachial artery before and after pacing to 140 beats/min for 4 minutes. Myocardial ischemia was assessed by determination of transmyocardial lactate extraction or production. Ibuprofen (800 mg) or placebo was administered orally 2 hours before cardiac catheterization. Patients were classified into 4 groups on the basis of administration of placebo or ibuprofen and the presence or absence of myocardial ischemia as determined by demonstration of lactate extraction or production after atrial pacing. In patients with lactate extraction, no significant efflux of cathepsin D or thromboxane B2 occurred after pacing. In patients with lactate production given placebo, a 64 +/- 25% increase in the thromboxane B2 level and a 113 +/- 37% increase in cathepsin D activities occurred in the coronary sinus effluent sampled after pacing. In contrast, in patients with comparable coronary artery disease and comparable lactate production who were given ibuprofen, no release of thromboxane B2 (p = 0.05 compared with patients given placebo) or cathepsin D (p less than 0.01 compared with patients given placebo) occurred after pacing-induced ischemia. These findings suggest that ibuprofen stabilizes membranes and prevents platelet-activated release of thromboxane A2 in pacing-induced myocardial ischemia.

Postoperative monitoring of myocardial oxygen tension: experience in 51 coronary artery bypass patients

Following a preliminary feasibility report, polarographic monitoring of myocardial tissue O2 tension (Pmo2) in 51 coronary bypass patients has been accomplished. In this context, the influence of rapid atrial pacing (RAP), O2 inhalation, and intra-aortic balloon assistance (IAB) was statistically analyzed using Wilcoxon sign-rank and Student's t-tests. Electrodes were implanted in revascularized and nonrevascularized areas for comparison (24.0 +/- 1.1; and 26.3 +/- 1.8 mmHg Pmo2, p, not significant). Increasing myocardial O2 demand with RAP caused a 6% PmO2 drop (p less than 0.01). A 70% O2 inhalation increased Pmo2 by 30% (p less than 0.01). In 5 cases the benefit of IAB was confirmed by a 41% increase in Pmo2 (p = 0.02). These data support the clinical usefulness of polarographic Pmo2 as a measure of regional myocardial oxygenation. In addition to early recognition of intraoperative or postoperative graft failure previously reported, the efficacy of various therapeutic interventions can be more precisely determined.

Leukocyte-derived interferon (alpha) in human breast carcinoma. The American Cancer Society phase II trial

A multi-institutional trials program was initiated to define the effects of interferons in disseminated human breast carcinoma. Interferon alpha, prepared from buffy coats, was administered intramuscularly at 3 x 10(6) U daily for an initial period of 28 days. Of 23 patients who entered the program, five had an objective partial response of 92 days mean duration at diverse sites of involvement. Patients who responded were significantly older (p = 0.05) than nonresponders. Dose escalation in eight patients did not result in any clear evidence of additional responses. Major toxicities were fatigue, anorexia with weight loss, and reversible leukopenia (less than 3.5 x 10(9) leukocytes/L in 16 patients). Natural killer cell and antibody-dependent cell-mediated cytotoxicity were significantly (p less than 0.05) enhanced 48 hours after interferon administration began but subsequently declined despite continued therapy. Serum beta 2-microglobulin concentration increased on day 15 (p less than 0.05) and remained significantly elevated on day 22 (p less than 0.005). Peak interferon titers (mean, 62 U) occurred 6 hours after interferon was started, varied widely between patients, and were higher and more persistent with dose escalation. Once an optimal dose is defined, prospectively randomized trials will define what role interferons may have in systemic therapy of breast carcinoma.

Monitoring regional myocardial function after myocardial revascularization

A system using only small platinum electrodes for monitoring intramyocardial polarographic oxygen tension (MP02), electrograms (ECG), and impedance-derived wall motion (WM) was experimentally tested and clinically implemented. In nine open-chest, anesthetized dogs. two platinum electrodes were inserted along the subepicardial direction of the muscle fibers. As verified by cinefluoroscopy, WM corresponded to changes in distance between the platinum electrodes (r = 0.91 +/- 0.02). The system responded to a 10 minute occlusion of the left anterior descending coronary artery (LAD) as follows: Dyskinetic WM appeared in 10 seconds (p less than 0.05); MP02 decreased (26.4 +/- 1.8 to 14.8 +/= 1.9 mm Hg, p less than 0.05) in 1 minute; ST segments increased (4.8 +/- 1.5 to 12.3 +/- 3.1 mV, p less than 0.05) in 3 minutes. On reperfusion, WM, ST segments, and MP02 normalized in 15 seconds, 30 seconds, and 1 minute, respectively. Hence, ischemia affects WM more acutely than either ECG or MP02. In five patients, ischemic changes before coronary bypass were reversed over 5 days: MP02 (17.4 +/-; 1.9 to 19.6 +/-1.7 mm Hg), ST segment (2.2 +/- 6 to 1.0 +/- 0.4 mV), and WM returned to normal. Thus a system has been designed which simultaneously monitors regional WM, MP02, and ECG. The method has proved to be a sensitive and practical approach for assessing perioperative myocardial function.

Lactate metabolism as a prognostic index in unstable angina

Fifty patients evaluated because of unstable angina were followed up for a mean period of 63.7 months. Analysis of transmyocardial lactate metabolism was performed in all patients in addition to coronary angiography and ventriculography. All patients had at least one coronary lesion of great than 75%. Although technically feasible, aortocoronary bypass surgery was not performed on initial hospitalization and all patients were treated medically. Patients were divided into two groups on the basis of lactate metabolism; group A lactate production great than 15%, group B lactate production less than 15% or lactate extraction. There was no difference in left ventricular end-diastolic pressure or ejection fraction between the two groups. A coronary score index was higher in group A than group B (5.45 +/- 2.2 vs 3.13 +/- 1.2) (p less than 0.05). The incidence of myocardial infarction was higher in group A than group B in hospital (44.4% vs. 4.3%, p less than 0.05), and long term (70.3% vs. 17.3%, p less than 0.05). Mortality was higher in group A than group B in hospital (25.9% vs. 0%, p less than 0.05) and long term (66.7% vs. 13%, p less than 0.05). Analysis of lactate metabolism thus provides a prognostic index in unstable angina which complements information obtained by coronary angiography and ventriculography.

Effects of the Valsalva maneuver on myocardial ischemia in patients with coronary artery disease

The influence of the Valsalva maneuver (VM) on myocardial ischemia was evaluated in 24 patients with coronary heart disease. Clinical and hemodynamic responses to the VM were studied during acute ischemia manifested by angina pectoris with transient left ventricular (LV) dysfunction and compared with responses during nonischemic intervals. In the absence of evidence for acute ischemia (angina and increased LV end-diastolic pressure), six patients had abnormal hemodynamic responses to the VM. Five had lack of systolic pressure overshoot and in one, systolic pressure did not decline during straining. When the VM was performed during an ischemic episode, 14 patients had abnormal responses (12 with lack of overshoot in phase IV and two with lack of systolic pressure decline in phase II). In 18 patients a prompt decline in LV end-diastolic pressure occurred with the disappearance of angina during the VM. These changes uniformly occurred during the latter part of straining (VM phase II) as cardiac size and systolic pressure declined. No adverse effects occurred when a VM was performed during acute ischemia. Our observations suggest that the VM abruptly reduces determinants of cardiac oxygen demand, relieving acute ischemia without harmful effects.

Detection of thromboxane B2 in peripheral blood of patients with Prinzmetal's angina

The plasma levels of thromboxane B2 (TxB2) were determined by radioimmunoassay in 6 consecutive patients with Prinzmetal's angina and in 9 healthy volunteers. In the normal group TxB2 was not detectable (= 0.5 pmoles/ml), while in patients with variant angina TxB2 was consistently detected (1.5-140 pmole/ml).

Improved oxygenation of ischemic myocardium by hemodilution with stroma-free hemoglobin solution

Experiments were conducted in anesthetized open-chest dogs subjected to occlusion of the left anterior descending coronary artery for three hours. The oxygenation of myocardial tissue was monitored by a polarographic technique capable of recording simultaneously the oxygen tension (Po2) of myocardial tissue and electrograms. Ischemic injury was monitored by means of ST-segment elevations on myocardial and epicardial electrograms. The volume of the myocardial infarct was measured at the end of each experiment by incubation of transverse slices of left ventricle in a solution of nitroblue tetrazolium and by separation of the unstained (ischemic) from the stained (normal) portions. In one group of dogs, hemodilution was performed after 15 minutes of ischemia by exchanging blood with a stroma-free hemoglobin solution (from a hematocrit reading of 45 +/- 3 percent to 23 +/- 2 percent). Changes occurring in this group were compared with those occurring in dogs that did not undergo hemodilution, underwent hemodilution with dextran 75, or were transfused with whole blood. Hemodilution with hemoglobin reduced aortic and left ventricular filling pressures while increasing coronary blood flow, increased myocardial Po2 from 2 +/- 2 mm Hg to 8 +/- 2 mm Hg (P less than 0.005), lowered the ST-segment elevation of both myocardial and epicardial electrograms, and reduced the volume of the myocardial infarct. These effects were unmatched by hemodilution with dextran or infusion of whole blood.

Improved survival after coronary bypass surgery in patients with poor left ventricular function: role of intraaortic balloon counterpulsation

The operative mortality rate of aortocoronary bypass surgery in 23 patients with poor left ventricular function (ejection fraction 0.30 or less) operated on in 1973-74 was 34.7 percent. The incidence rate of operative myocardial infarction was 30.4 percent. In an attempt to improve survival, intraaortic balloon counterpulsation was used therafter in 25 similar patients. Counterpulsation was instituted preoperatively and continued intra- and postoperatively for 2 to 5 days. Preoperative studies revealed an "unloading" effect of the left ventricle, with significant reductions of systolic arterial blood pressure, end-diastolic pulmonary arterial pressure and end-diastolic left ventricular volume and pressure. Metabolic improvement was demonstrated by the lesser production of myocardial lactate after pacing-induced tachycardia when the ventricle was balloon-assisted. Intraoperatively, blood flow through the vein graft was found to increase with counterpulsation. The rate of operative myocardial infarction was reduced to 4 percent and the mortality rate to 8 percent. In patients who have sustained a significant loss of functioning myocardium, the beneficial hemodynamic and metabolic effects of intraaortic balloon counterpulsation appear to prevent furhter, possibly critical, myocardial damage in the perioperative period.

Spectrum of coronary arterial spasm. Clinical, angiographic and myocardial metabolic experience in 29 cases

A relationship of coronary arterial spasm to variant angina pectoris, subendocardial ischemia, major ventricular arrhythmias and myocardial infarction has been demonstrated. In 29 patients, spasm was angiographically observed in normal-appearing coronary arteries (7 patients) as well as superimposed on various degrees of coronary atherosclerotic obstruction (22 patients). All patients experienced an atypical anginal syndrome;16 patients also experienced typical exertional angina. Coronary spasm appeared to be a major contributory factor in eight occurrences of myocardial infarction and in 11 incidents of ventricular tachycardia, ventricular fibrillation and heart block. Coronary spasm in the 29 cases was distributed in the following fashion: left main trunk, 6 cases; right main trunk, 12 cases; proximal left anterior descending artery, 13 cases; proximal circumflex artery, 1 case; distal left anterior descending artery, 1 case; and distal circumflex artery, 2 cases. In 5 cases coronary spasm was noted at multiple sites.

Glucocorticoid protection of the myocardial cell membrane and the reduction of edema in experimental acute myocardial ischemia

A possible protective effect of glucocorticoids on the ischemic myocardium was investigated in in situ dog hearts subjected to regional ischemia and in isolated rat hearts subjected to global ischemia. In the whole-animal preparation, the left anterior descending coronary artery (LAD) was occluded for 3 hours, or for 2 1/2 hours followed by 30 minutes of reperfusion. Dexamethasone phosphate was randomly administered (20 mg. per kilogram intravenously) after 15 minutes of ischemia. Its effects were studied on the following: (1) myocardial cell membrane integrity, using electron microscopic examination of tissue biopsies treated with colloidal lanthanum; (2) myocardial water content, measuring the wet/dry weight of myocardial tissue; (3) ischemic injury, by a count of fuchsinophilic cells at light microscopy. In isolated rat hearts, ischemia was produced by a 60 per cent reduction of coronary flow. Randomized hearts were perfused for 2 hours with dexamethasone, 15 mg. per milliliter in buffered salt solution. Study included determination of tissue water content and coronary vascular resistance. Lanthanum was confined to the extracellular spaces in normal dog myocardium, but it was found all intracellularly after 3 hours of ischemia or after reperfusion. This was associated with morphologic changes characteristic of irreversible cell injury. In the hearts treated with dexamethasone, lanthanum remained excluded from the cells, water content was less (p less than 0.005), and fuchsinophilia less severe (p less than 0.005). Likewise, water content was less (p less than 0.005) and the increase in coronary vascular resistance resulting from ischemia less severe (p less than 0.005) in the dexamethasone-treated isolated rat hearts. Thus dexamethasone administered in pharmacologic doses, early, appeared to stabilize the cell membrane, limit myocardial edema, and reduce the severity of injury, both during ischemia and upon reperfusion.

Monitoring tissue oxygenation of the heart after myocardial revascularization

A polarographic technique capable of simultaneous monitoring of myocardial tissue oxygen tension (MPO2) and intramyocardial electrograms by way of the same electrodes has been developed. Initially, the method was evaluated in dogs to verify the appropriateness of the directional changes of MPO2 in function of selected determinants of myocardial oxygen supply (regional coronary blood flow, arterial blood oxygen tension) and demand (heart rate, force of ventricular contraction). A combined reduction of MPO2 and elevation of the S-T segment in the corresponding electrograms was observed only when a 50 percent or greater reduction of blood flow to the sampled area was effected. Subsequently, in nine patients undergoing aortocoronary bypass surgery, MPO2 was measured from 48 areas for 2 weeks postoperatively. In 11 normal and 31 revascularized areas, MPO2 increased during the postoperative period. In four areas subsequently found to be supplied by occluded grafts MPO2 decreased from 12.7 +/- 3.1 (mean +/- standard error) to 10.1 +/- 3.3 mm Hg (P less than 0.05). In two areas, MPO2 decreased during the 3rd postoperative day from 16 to 3 and from 14 to 4.2 mm Hg, respectively. This reduction was attended by a significant rise in the S-T segment of the corresponding electrograms. This finding preceded by 24 hours standard electrocardiographic evidence of myocardial infarction. This technique appears to be sensitive and reliable, and thereby capable of enhancing the management of patients during the high risk early postoperative period after coronary bypass surgery.

Comparative hemodynamic effects of placebo and oral isosorbide dinitrate in patients with significant coronary artery disease

Comparative hemodynamic effects of placebo and 10 mg of oral isosorbide dinitrate were studied in patients with significant coronary artery disease (larger than or equal to 75 per cent lumen narrowing) proved angiographically. Isosorbide dinitrate or placebo was given to eight and 10 patients, respectively, in a double-blind fashion. Cardiac performance at rest and during supine leg exercise was evaluated before and 60 minutes after drug administration. In the resting state, isosorbide dinitrate compared to placebo significantly reduced the left ventricualr (systolic and diastolic), mean pulmonary artery and mean aortic pressures, cardiac index, stroke index, left ventricular work index, stroke work index, and mean systolic ejection rate. Isosorbide dinitrate also significantly reduced left ventricular (systolic and diastolic and mean pulmonary artery pressures during exercise. This study indicates that 10 mg of isosorbide dinitrate has a significant influence on ischemic left ventricular dysfunction 60 minutes after its oral administration.

Relationship of anginal symptoms to lung mechanics during myocardial ischemia

The anginal syndrome (AP) typically includes sensations of chest tightness or difficulty in breathing. Left ventricular (LV) dysfunction during myocardial ischemia incident with AP is now well documented. Since secondary alterations in lung mechanics could relate to these symptoms, we examined airway resistance (Raw), lung volume (TGV), lung compliance (C L ), and LV pressure-volume relations during pacing-induced AP.

LV end-diastolic pressure (EDP) increased suddenly with AP, (mean + 41%, p < 0.01), without change in end-diastolic volume (EDV). LV distensibility (EDV/EDP) decreased abruptly, (–37%, P < 0.01), with reduction in airway conductance (1/Raw/TGV), (–40%, P < 0.05), and C L (–27%, P < 0.05). When AP was relieved, these changes returned toward preangina levels.

Ischemia-induced LV dysfunction abruptly increases LVEDP. The resulting increased pulmonary capillary pressure effects an alteration of lung mechanics consisting of increasing Raw and reduced C L . The changes in ventilatory effort which ensue may be interpreted as chest tightness, heaviness, or constriction by the AP patient.