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Left ventricular hypertrophy in mild hypertension: Correlation with exercise blood pressure
386
Brief
Communications
February. 1985 Heart Journal
American
Fig. 1. Composite drawing of the described partial removal of a segment of the polymer
wire technique. The suture wire (A) is first prepared by coating to expose the wire proper (B), leaving the distal
segmentintact. This end is then inserted into the previously positioned catheter in the right ventricular cavity (C). The proximal
exposed wire and skin suture wire are attached
to the external
pulse generator
(0).
I. Intraoperative lead measurements
Table
Endocardial Epicardial* Epicardialt *Screw-in
t&b
Resistance ($2)
R wave sensing (m V)
961 900 604
9.8 8.5 10.6
McNamara D: Congenital complete atrioventricular block: Clinical and electrophysiologic predictors of need for pacemaker insertion. Am J Cardiol 48:1098, 1981. 3. Floresco N: Rappel a la vie par l’excitation direct due coeur. .J Physiol 7:797, 1905. 4. Benson D, Dunnigan A, Sterba R, Benditt D: Atria1 pacing from the eosphagus in the diagnosis and management of tachycardia and palpitations. J Pediatr 102:40, 1983.
-.Threshold wi 1.6 1.6 1.6
-
electrode.
electrode.
cardial wire and epicardial leads (Table I). Follow-up examination 2 months following permanent pacemaker implantation revealed improvement in the child’s clinical condition. Transvenous pacing is not a new concept and the wire technique describedhere is the clinical modification of a method first described in dogs in 1905by Floresco.3The application of this technique in a smallinfant hasnot been previously reported. Although transesophagealventricular pacing has been described in an older child,4 the availability of necessarymaterial and technical easeof insertion
make the catheter
and wire method
an accept-
able alternative in short-term cardiac pacing when other techniques are not feasible. REFERENCES
1. Michaelsson M, Engle MA: Congenital complete heart block: An international study of the natural history. Cardiovasc Clin 4:85, 1972. 2. Karpawich P, Gillette P, Garson A, Hesslein P, Porter C,
Left ventricular hypertrophy in mild hypertension: Correlation with exercise blood pressure Dilip Nathwani, Richard A. Reeves,M.D., F.R.C.P.(C), Ana Marquez-Julio, M.D., F.R.C.P.(C), and Frans H. H. Leenen, M.D., Ph.D. Toronto,
From ment
Ontario,
Canada
the Hypertension Unit, Division of Clinical of Medicine, Toronto Western Hospital.
Pharmacology,
Depart-
Supported by an elective Scholarship from the British Chest. Heart and Stroke Association (D. Nathwani); by a Fellowship from the Medical Research Council of Canada (Dr. Reeves): and by a Research Scholarship from the Canadian Heart Foundation (Dr. Leenen). Reprint requests: Frans H. H. Leenen, M.D., of Clinical Pharmacology. Toronto Western Toronto. Ontario M5T 2%. Canada.
Hypertension Hospital,
399
Unit. Division Bathurst St.,
Volume
109
Number
2
LV
Brief
MASS
INDEX
> 0 X
0
0 x
x 0 X
@
x 0
0
0
120
c
0
L
0 0
X
100
R p
= -
0. 68 0.01
L----e 160
200
160 SUBMAXSP
220
240
Hg)
Fig. 1. Correlation of LV massindex with systolic blood pressure during submaximal treadmill exercise in 20 young mildly hypertensive patients. X = patients engaging in regular physical activity. (Upper limit of normal LV massindex5 is approximately 100 gm/m*.)
Communications
387
The left ventricular mass,calculated from echo cardiographic data using an anatomically validated formula, was used to determine the left ventricular mass index (LVMI = LV mass/bodysurfacearea). By multiple regression analysisof LVMI on the three measuresof SBP, age, and activity level, using a step-down approach,6 only SUBMAXSP and activity were found to be significant (p < 0.05) components of the regression (Fig. 1). The correlation coefficients for these two independent variables taken singly were +0.57 and +0.44, respectively, yielding a multiple correlation coefficient of r = +0.68 (p < 0.01). Activity status and SUBMAXSP were not correlated with one another (r = +O.ll, p = NS). Even when evaluated as single independent variables, the CASUALSP and CLINICSP were not correlated with LVMI (r = +0.21 and r = -0.01, respectively, both p = NS). Treadmill exercisetesting permits easydetermination of SBP responseto exercise, i.e., SUBMAXSP. This quantity appearsto correlate better with severity of LVH (and probably with likelihood of morbidity) than doesthe resting SBP, a conclusionin agreementwith the findings of other studies.3,1 In order to optimize the treatment of mild hypertension, it may be necessaryto considerthe effect of therapy on not only resting, but also on exercise BP. REFERENCES
1. KannelWB, GordonT, CastelliWP, MargolisdR: ElectroLeft ventricular hypertrophy (LVH) is an important graphic left ventricular hypertrophy and risk of coronary independent risk factor for cardiovascular disease.‘-? heart disease: The Framingham study. Ann Intern Med 72:813, 1970. Hypertensive target organ damage including ECG LVH 2. Kannel WB, Gordon T, Offutt D: Left ventricular hypertrorelates more closely to the average blood pressure (BP) phy by electrocardiogram: Prevalence, incidence and mortalmeasuredduring daily activity than to casual clinic BP ity in the Framingham study. Ann Intern Med 71:89, 1969. measurements.3 Recently, Devereux et al4 showedthat in 3. Sokolow M, Werdegar D, Kain HK, Hinman AT: Relationmild hypertensive patients the degreeof echocardiograpship between level of blood pressure measured casually and by portable recorders and severity of complications in essenhit LVH relates more closely to systolic blood pressure tial hypertension. Circulation 34:279, 1966. (SBP) during the stressof work (T = 0.5) than to resting 4. Devereux RB, Pickering TG, Harshfield GA, Kleinert HD, SBP in the clinic (r = 0.24). We hypothesized that the Denby L, Clark L, Pregibon D, Jason M, Kleiber B, Borer JS, SBP during active physical exercise would be another Laragh JH: Left ventricular hypertrophy in patients with hypertension: Importance of blood pressure response to important determinant of the degree of LVH present, regularly recurring stress. Circulation 68:470, 1983. especially in those patients with only mild BP elevations 5. Devereux RB, Reichek N: Echocardiographic determination at rest. of ventricular mass in man: Anatomic validation of the In a retrospective study, the relation of echocardiograpmethod. Circulation 55613, 1977. hit LVH and resting versus exerciseSBP was analyzed in 6. Snedecor GW, Cochran WG: Statistical Methods. 6th ed. Ames, Iowa, 1967, Iowa State University Press, p 413. 20 young (18 to 40 years) subjects(19 men, 1 woman) with mild hypertension, defined as resting upright SBP of 140 to 150 mm Hg or diastolic BP of 90 to 105 mm Hg on at least two occasions.Seventeen patients were untreated Neural circulatory control in the and three had discontinued therapy at least 6 months prior to the study. Seven patients who engagedin regular hyperdynamic circulatory state syndrome dynamic exerciseor who had physically demanding occupations were classedasactive. M-mode echocardiography, David S. Goldstein, M.D., Ph.D., and treadmill testing using the Bruce protocol, and BP meaHarry R. Keiser, M.D. Bethesda, Md. surements were performed within a 2-month period. Three upright SBP measureswere used: CLINICSP (SBP after 15 minutes rest, averaged for three (n = 12) or two From the Hypertension-Endocrine Branch, National Heart, Lung, and (n = 8) clinic visits); CASUALSP, the SBP after standing Blood Institute, National Institutes of Health. quietly for 15 minutes prior to treadmill testing; and Reprint requests: David S. Goldstein, M.D., Bldg. 10 8C118. NHLBI, NIH, Bethesda, MD 20205. SUBMAXSP, the systolic BP at submaximal exercise.
Brief
Communications
February. 1985 Heart Journal
American
Fig. 1. Composite drawing of the described partial removal of a segment of the polymer
wire technique. The suture wire (A) is first prepared by coating to expose the wire proper (B), leaving the distal
segmentintact. This end is then inserted into the previously positioned catheter in the right ventricular cavity (C). The proximal
exposed wire and skin suture wire are attached
to the external
pulse generator
(0).
I. Intraoperative lead measurements
Table
Endocardial Epicardial* Epicardialt *Screw-in
t&b
Resistance ($2)
R wave sensing (m V)
961 900 604
9.8 8.5 10.6
McNamara D: Congenital complete atrioventricular block: Clinical and electrophysiologic predictors of need for pacemaker insertion. Am J Cardiol 48:1098, 1981. 3. Floresco N: Rappel a la vie par l’excitation direct due coeur. .J Physiol 7:797, 1905. 4. Benson D, Dunnigan A, Sterba R, Benditt D: Atria1 pacing from the eosphagus in the diagnosis and management of tachycardia and palpitations. J Pediatr 102:40, 1983.
-.Threshold wi 1.6 1.6 1.6
-
electrode.
electrode.
cardial wire and epicardial leads (Table I). Follow-up examination 2 months following permanent pacemaker implantation revealed improvement in the child’s clinical condition. Transvenous pacing is not a new concept and the wire technique describedhere is the clinical modification of a method first described in dogs in 1905by Floresco.3The application of this technique in a smallinfant hasnot been previously reported. Although transesophagealventricular pacing has been described in an older child,4 the availability of necessarymaterial and technical easeof insertion
make the catheter
and wire method
an accept-
able alternative in short-term cardiac pacing when other techniques are not feasible. REFERENCES
1. Michaelsson M, Engle MA: Congenital complete heart block: An international study of the natural history. Cardiovasc Clin 4:85, 1972. 2. Karpawich P, Gillette P, Garson A, Hesslein P, Porter C,
Left ventricular hypertrophy in mild hypertension: Correlation with exercise blood pressure Dilip Nathwani, Richard A. Reeves,M.D., F.R.C.P.(C), Ana Marquez-Julio, M.D., F.R.C.P.(C), and Frans H. H. Leenen, M.D., Ph.D. Toronto,
From ment
Ontario,
Canada
the Hypertension Unit, Division of Clinical of Medicine, Toronto Western Hospital.
Pharmacology,
Depart-
Supported by an elective Scholarship from the British Chest. Heart and Stroke Association (D. Nathwani); by a Fellowship from the Medical Research Council of Canada (Dr. Reeves): and by a Research Scholarship from the Canadian Heart Foundation (Dr. Leenen). Reprint requests: Frans H. H. Leenen, M.D., of Clinical Pharmacology. Toronto Western Toronto. Ontario M5T 2%. Canada.
Hypertension Hospital,
399
Unit. Division Bathurst St.,
Volume
109
Number
2
LV
Brief
MASS
INDEX
> 0 X
0
0 x
x 0 X
@
x 0
0
0
120
c
0
L
0 0
X
100
R p
= -
0. 68 0.01
L----e 160
200
160 SUBMAXSP
220
240
Hg)
Fig. 1. Correlation of LV massindex with systolic blood pressure during submaximal treadmill exercise in 20 young mildly hypertensive patients. X = patients engaging in regular physical activity. (Upper limit of normal LV massindex5 is approximately 100 gm/m*.)
Communications
387
The left ventricular mass,calculated from echo cardiographic data using an anatomically validated formula, was used to determine the left ventricular mass index (LVMI = LV mass/bodysurfacearea). By multiple regression analysisof LVMI on the three measuresof SBP, age, and activity level, using a step-down approach,6 only SUBMAXSP and activity were found to be significant (p < 0.05) components of the regression (Fig. 1). The correlation coefficients for these two independent variables taken singly were +0.57 and +0.44, respectively, yielding a multiple correlation coefficient of r = +0.68 (p < 0.01). Activity status and SUBMAXSP were not correlated with one another (r = +O.ll, p = NS). Even when evaluated as single independent variables, the CASUALSP and CLINICSP were not correlated with LVMI (r = +0.21 and r = -0.01, respectively, both p = NS). Treadmill exercisetesting permits easydetermination of SBP responseto exercise, i.e., SUBMAXSP. This quantity appearsto correlate better with severity of LVH (and probably with likelihood of morbidity) than doesthe resting SBP, a conclusionin agreementwith the findings of other studies.3,1 In order to optimize the treatment of mild hypertension, it may be necessaryto considerthe effect of therapy on not only resting, but also on exercise BP. REFERENCES
1. KannelWB, GordonT, CastelliWP, MargolisdR: ElectroLeft ventricular hypertrophy (LVH) is an important graphic left ventricular hypertrophy and risk of coronary independent risk factor for cardiovascular disease.‘-? heart disease: The Framingham study. Ann Intern Med 72:813, 1970. Hypertensive target organ damage including ECG LVH 2. Kannel WB, Gordon T, Offutt D: Left ventricular hypertrorelates more closely to the average blood pressure (BP) phy by electrocardiogram: Prevalence, incidence and mortalmeasuredduring daily activity than to casual clinic BP ity in the Framingham study. Ann Intern Med 71:89, 1969. measurements.3 Recently, Devereux et al4 showedthat in 3. Sokolow M, Werdegar D, Kain HK, Hinman AT: Relationmild hypertensive patients the degreeof echocardiograpship between level of blood pressure measured casually and by portable recorders and severity of complications in essenhit LVH relates more closely to systolic blood pressure tial hypertension. Circulation 34:279, 1966. (SBP) during the stressof work (T = 0.5) than to resting 4. Devereux RB, Pickering TG, Harshfield GA, Kleinert HD, SBP in the clinic (r = 0.24). We hypothesized that the Denby L, Clark L, Pregibon D, Jason M, Kleiber B, Borer JS, SBP during active physical exercise would be another Laragh JH: Left ventricular hypertrophy in patients with hypertension: Importance of blood pressure response to important determinant of the degree of LVH present, regularly recurring stress. Circulation 68:470, 1983. especially in those patients with only mild BP elevations 5. Devereux RB, Reichek N: Echocardiographic determination at rest. of ventricular mass in man: Anatomic validation of the In a retrospective study, the relation of echocardiograpmethod. Circulation 55613, 1977. hit LVH and resting versus exerciseSBP was analyzed in 6. Snedecor GW, Cochran WG: Statistical Methods. 6th ed. Ames, Iowa, 1967, Iowa State University Press, p 413. 20 young (18 to 40 years) subjects(19 men, 1 woman) with mild hypertension, defined as resting upright SBP of 140 to 150 mm Hg or diastolic BP of 90 to 105 mm Hg on at least two occasions.Seventeen patients were untreated Neural circulatory control in the and three had discontinued therapy at least 6 months prior to the study. Seven patients who engagedin regular hyperdynamic circulatory state syndrome dynamic exerciseor who had physically demanding occupations were classedasactive. M-mode echocardiography, David S. Goldstein, M.D., Ph.D., and treadmill testing using the Bruce protocol, and BP meaHarry R. Keiser, M.D. Bethesda, Md. surements were performed within a 2-month period. Three upright SBP measureswere used: CLINICSP (SBP after 15 minutes rest, averaged for three (n = 12) or two From the Hypertension-Endocrine Branch, National Heart, Lung, and (n = 8) clinic visits); CASUALSP, the SBP after standing Blood Institute, National Institutes of Health. quietly for 15 minutes prior to treadmill testing; and Reprint requests: David S. Goldstein, M.D., Bldg. 10 8C118. NHLBI, NIH, Bethesda, MD 20205. SUBMAXSP, the systolic BP at submaximal exercise.