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Closing Capacity vs Closing Volume
It is quite evident, from our experience with this patient, that failure to recognize his dextrocardia could have led to incorrect diagnosis of left bundle branch block and myocardial infarction. This error was avoided by observation of the abnormal P wave morphology in limb and chest leads, pointing to the correct diagnosis. ACKNOWLEDGMENTS: The authors thank Drs. Irwin Hoffman, Robert I. Hamby and Paulette Smedresman for very kindly reviewing the manuscript and Mr. Steven B. Levine and Mr. Sidney Shapiro for technical assistance.
/awahar Mehta, M.D., Melvin Young, M.D. and Israel Pine, M.D. School of Medicine ofthe State University of N ew York at Stony Brook
expiratory How of 0.5 liters/sec, the VC of the CV test is presumed to be ~ the FVC, which is shown as 5.0 liters. The CV must be ~ 1.88 liters. With RV of 1.9 liters, this gives a CC/TLC ratio ~ 55 as shown. A smaller value for CV, such as the 1.35 liters consistent with the indicated ev Ive of 27 percent, could not give a CC/TLC of 55 percent. CC/TLC is more sensitive than CV Ive because it incorporates the RV, which increases early in the course of obstructive airway disease.v" No greater information is gained from utilizing CC/TLe than from noting both ev Ive and RV. Since the RV shown is normal, it is unlikely that CV IVC will be normal if CC/TLC is high. It is unfortunate that the mathematic inconsistency in the illustration in question should confuse this point.
Albert Miller, M.D., F.C.C.P. and Ming Chuang, M.D. Mount Sinai Hospital New York
REFERENCES
1 Rosenberg HN, Rosenberg IN: Simultaneous association of situs inversus, coronary heart disease and hiatus hernia. Ann Intern Med 30:851-859, 1949 2 Perloff JK: The Clinical Recognition of Congenital Heart Disease. Philadelphia, WB Saunders Co, pp 14-18, 1970 3 Fischer DC: Combination of dextrocardia, bundle branch block and myocardial infarction. Case report with vector analysis of EKG. Am J CardioI2:770-772, 1958 4 Jacoby WJ Jr, Jacobson WA: Dextrocardia complicated by myocardial infarction. Am J Cardioll: 119-122, 1963 5 Kirk ED Jr: Transient bundle branch block due to myocardial infarction in a patient with dextrocardia with situs inversus. Am J CardioI16:297-299, 1965 6 Waller AD: On the electromotive changes connected with the beat of the mammalian heart and of the human heart in particular. Phil Trans Roy Soc (London) 180:169, 1889 7 Walker WJ, Richmond GH: Posterior ventricular aneurysm in patient with dextrocardia and situs inversus. Am Heart J 48:275-279, 1954
REFERENCES
1 Buist AS, Van Fleet DL, Ross BB: A comparison of conventional spirometric tests and the test of closing volume in an emphysema screening center. Am Rev Resp Dis 107:735-743,1973 2 Bates DV: Chronic bronchitis: Report on third and fourth stages of co-ordinated study in Department of Veterans Affairs. Can Med Serv J 22:1,1966 3 McFadden ER Jr, Linden DA: A reduction in maximum mid-expiratory flow rate: A spirographic manifestation of small airway disease. Am J 52:725-737, 1972
Moo
Arterial Hypertension In a Rural African Community
Closing Capacity vs Closing Volume
To the Editor:
To the Editor:
A preliminary investigation done at a referral hospital that serves a rural unindustrialized community has disclosed that hypertension is prevalent. The projected incidence would be about 7 percent of the population. This estimate does compare well with the figures from other reports.l" Primary hypertension was present in 92 percent of the ~9 arterial hypertension cases analyzed. Secondary causes were nearly all renal, on the basis of either chronic glomerulonephritis or chronic pyelonephritis. A number of common associated factors were evident, particularly obesity and diabetes mellitus without nephropathy. It is noteworthy that there emerged ne special features regarding social status, education; or habitat among the many factors that were subjected to scrutiny in relation to essential hypertension The incidence in the two sexes was about equal, while
In an article in Chest (64:495-499, 1973), Dr. Buist repeated her claim that closing capacity (specifically, CC/TLC) is "of significantly greater sensi.. tivity" than closing volume (specifically CV Ive) in the early detection of airway obstruction. 1 This claim was supported by her Figure 3, a N~eV record of a 61-year-old symptomatic smoker, which shows "normal" residual volume (RV) and CV/VC but "abnormal" ee/TLC. Unfortunately, these designations are not, and cannot, be accurate, and are inconsistent with the graphic record shown. As careful a measurement as the size of the reproduction permits reveals that ev is 37.5 percent of the recorded VC, not 27 percent as indicated. This is an abnormal CV IVC ratio. At an
128 COMMUNICATIONS TO THE EDITOR
CHEST, 68: 1, JULY, 1975
/awahar Mehta, M.D., Melvin Young, M.D. and Israel Pine, M.D. School of Medicine ofthe State University of N ew York at Stony Brook
expiratory How of 0.5 liters/sec, the VC of the CV test is presumed to be ~ the FVC, which is shown as 5.0 liters. The CV must be ~ 1.88 liters. With RV of 1.9 liters, this gives a CC/TLC ratio ~ 55 as shown. A smaller value for CV, such as the 1.35 liters consistent with the indicated ev Ive of 27 percent, could not give a CC/TLC of 55 percent. CC/TLC is more sensitive than CV Ive because it incorporates the RV, which increases early in the course of obstructive airway disease.v" No greater information is gained from utilizing CC/TLe than from noting both ev Ive and RV. Since the RV shown is normal, it is unlikely that CV IVC will be normal if CC/TLC is high. It is unfortunate that the mathematic inconsistency in the illustration in question should confuse this point.
Albert Miller, M.D., F.C.C.P. and Ming Chuang, M.D. Mount Sinai Hospital New York
REFERENCES
1 Rosenberg HN, Rosenberg IN: Simultaneous association of situs inversus, coronary heart disease and hiatus hernia. Ann Intern Med 30:851-859, 1949 2 Perloff JK: The Clinical Recognition of Congenital Heart Disease. Philadelphia, WB Saunders Co, pp 14-18, 1970 3 Fischer DC: Combination of dextrocardia, bundle branch block and myocardial infarction. Case report with vector analysis of EKG. Am J CardioI2:770-772, 1958 4 Jacoby WJ Jr, Jacobson WA: Dextrocardia complicated by myocardial infarction. Am J Cardioll: 119-122, 1963 5 Kirk ED Jr: Transient bundle branch block due to myocardial infarction in a patient with dextrocardia with situs inversus. Am J CardioI16:297-299, 1965 6 Waller AD: On the electromotive changes connected with the beat of the mammalian heart and of the human heart in particular. Phil Trans Roy Soc (London) 180:169, 1889 7 Walker WJ, Richmond GH: Posterior ventricular aneurysm in patient with dextrocardia and situs inversus. Am Heart J 48:275-279, 1954
REFERENCES
1 Buist AS, Van Fleet DL, Ross BB: A comparison of conventional spirometric tests and the test of closing volume in an emphysema screening center. Am Rev Resp Dis 107:735-743,1973 2 Bates DV: Chronic bronchitis: Report on third and fourth stages of co-ordinated study in Department of Veterans Affairs. Can Med Serv J 22:1,1966 3 McFadden ER Jr, Linden DA: A reduction in maximum mid-expiratory flow rate: A spirographic manifestation of small airway disease. Am J 52:725-737, 1972
Moo
Arterial Hypertension In a Rural African Community
Closing Capacity vs Closing Volume
To the Editor:
To the Editor:
A preliminary investigation done at a referral hospital that serves a rural unindustrialized community has disclosed that hypertension is prevalent. The projected incidence would be about 7 percent of the population. This estimate does compare well with the figures from other reports.l" Primary hypertension was present in 92 percent of the ~9 arterial hypertension cases analyzed. Secondary causes were nearly all renal, on the basis of either chronic glomerulonephritis or chronic pyelonephritis. A number of common associated factors were evident, particularly obesity and diabetes mellitus without nephropathy. It is noteworthy that there emerged ne special features regarding social status, education; or habitat among the many factors that were subjected to scrutiny in relation to essential hypertension The incidence in the two sexes was about equal, while
In an article in Chest (64:495-499, 1973), Dr. Buist repeated her claim that closing capacity (specifically, CC/TLC) is "of significantly greater sensi.. tivity" than closing volume (specifically CV Ive) in the early detection of airway obstruction. 1 This claim was supported by her Figure 3, a N~eV record of a 61-year-old symptomatic smoker, which shows "normal" residual volume (RV) and CV/VC but "abnormal" ee/TLC. Unfortunately, these designations are not, and cannot, be accurate, and are inconsistent with the graphic record shown. As careful a measurement as the size of the reproduction permits reveals that ev is 37.5 percent of the recorded VC, not 27 percent as indicated. This is an abnormal CV IVC ratio. At an
128 COMMUNICATIONS TO THE EDITOR
CHEST, 68: 1, JULY, 1975