clin. Cardiol. 12, 91-96 (1989)
V. DALL’AGLIO, M.D., G, L. NICOLOSI, M.D., C. BUBELLI, M.D., F. ZARDO, M.D., D. PAVAN. M.D.., C. LESTUZZI, M.D., D. ZANUTTINI, M.D.
Divisione di Cardiologia, Ospedale Civile, Pordenone, Italy
Summary: We report 6 cases of dilated left ventricle with poor left ventricular function and coexisting systemic hypertension in whom left ventricular hypertrophy and normalization of left ventricular function and dimensions have been subsequently documented by M-mode and two-dimensional echocardiographic follow-up studies. Four patients were in New York Heart Association functional Class IV, one in Class III, and one in Class II when first seen. Normalization of left ventricular function and dimensions and features of left entricular hypertrophy (fractional shortening from 15.0+5.2 to 39.7 ±5.4, left ventricular end-diastolic diameter from 6.6±0.6 to 6.6+0.6 cm, left ventricular end-systolic diameter from 5.6±0.8 to 2.8+0.6 cm, left ventricular end-diastolic radius/posterior wall thickness from 3.1 ±0.5 to 2.0+0.4, interventricular septum thickness from 1.2 ±0.3 to 1.5±0.3 cm, left atrium from 4.6±0.6 to 3.5±0.9 cm) were achieved after adequate medical treatment at the end of the follow-up (11-39 months). It appears from this study that normalization of left ventricular dimensions and function with features of left ventricular hypertrophy can occur after adequate treatment in patients with echocardiographic findings of dilated and poorly contracting left ventricle and coexisting systemic hypertension. It is conceivable, in such cases, to classify the dilatation of the left ventricle as secondary and to suggest the hypothesis of a cause-effect relationship between therapy and normalization of left ventricular parameters with findings of left ventricular hypertrophy. Further studies are needed to clarify this phenomenon.
Address for reprints:
Dr. Vittorio Dall’Aglio
Received: November 10, 1987
Accepted with revision: October 20, 1988
A dilated and poorly contracting left ventricle can be due to a "primary" ("idiopathic") dilated cardiomyopathy (DCM) or can be "secondary" to a well-known cause.[1-3]
When systemic hypertension is present, the dilatation of the left ventricle and the poor left ventricular (LV) function can be considered as secondary.[1-3] The echocardiographic findings of DCM and of the dilated left ventricle due to systemic hypertension, however, may be similar.
In our laboratory, normalization of LV dimensions and function and features of LV hypertrophy have been demonstrated by M-mode and two-dimensional echocardiographic follow-up studies in 6 cases, whose initial findings were of dilated and poorly contracting left ventricle and coexisting systemic hypertension.
To our knowledge, this is the first echocardiographic documentation of normalization of left ventricular dimensions and function with findings of left ventricular hypertrophy in patients with long-standing chronic systemic hypertension and previous evidence of dilated and poorly contracting left ventricle.
Patients and Methods
The study group comprises 6 patients with systemic hypertension, 4 male and 2 female, with heart failure and echocardiographic features of dilated and poorly contracting left ventricle. The age range was 26-64 years (mean 49). Four patients underwent echocardiographic follow-up after 13, 22, 26, and 39 months; 2 patients underwent a first echocardiographic follow-up 21 days and 3 months later and a second echocardiographic follow-up 11 and 15 months, respectively, after the first examination. Two- dimensional echocardiograms were obtained using commercially available phased-array or mechanical sector scanners (Toshiba SSH 40A, Toshiba SSL 53M, Aloka SSD 720). Images were obtained from the parastemal, apical, and subcostal approaches to visualize cardiac chambers in the usual longitudinal, four-chamber and short-axis planes; intermediate planes were always recorded when necessary.[10,11] Positioning and manipulation of the transducer were optimized in order to achieve adequate endocardial definition. M-mode echocardiograms were also recorded at 50 mm/s paper speed using black and white photographic paper. The following M-mode parameters were analyzed: LVFS (left ventricular fractional shortening), LVEDD (left ventricular end-diastolic diameter), LVESD (left ventricular end-systolic diameter), PWTh (posterior wall thickness), R/Th (left ventricular end-diastolic radius/posterior wall thickness), IVSTh (interventricular septum thickness), IVS%Th (percentage of IVS systolic thickening), PW%Th (percentage of PW systolic thickening), LA (left atrium dimensions). Measurements were obtained blindly by two observers according to the Recommendations of the A.S.E. and given as the mean of the two observations. Paired t-test was used for statistical analysis. M-mode indexes of diastolic function were also studied (see Results). At the time of the first echocardiographic examination, relevant clinical data were: a history of systemic hypertension (duration of 3-7 years) was present in 4 cases. Mean blood pressure value range was 160-240 over 100-160 mmHg. Adequate therapeutic control of blood pressure had never been reached in these 4 patients. In the remaining 2 patients, it was not possible to know when high levels of blood pressure were first observed. In these two subjects, aged 26 and 57 years, blood pressure was 230/160 and 180/110 mmHg, respectively, at the first examination. Pour patients were in New York Heart Association (NYHA) functional Class IV, one in Class III, and one in Class II. There was no history of previous infective disease nor of alcohol abuse in any patient.
No patient had a clinical picture of acute infective disease. All patients were studied from a clinical-echo-cardiographic point of view.
Two patients smoked 20 cigarettes daily. In one case (CG, F, age 26), antivirus coxsackie, echo, influenza, and parainfluenza antibodies were obtained and were negative. No patient had valvular, ischemic, congenital, or specific heart muscle disease. Two patients were not treated; three patients had just started antihypertensive therapy 2, 5, and 21 days before the first echocardiogram. In one case, diuretics were started some time before without adequate blood pressure control.
At the time of the last echocardiographic follow-up, rele vant clinical data were: blood pressure normal in 4 patients, borderline in 2 patients. Four patients were in NYHA functional Class II, 2 in Class I. All 6 patients were on antihypertensive treatment (captopril and diuretics in 3 cases, captopril-diuretics and verapamil in 1 case, clonidine-diuretics and nifedipine in 1 case, prazosin and diuretics in 1 case).
At the end of the follow-up, echocardiograms of all 6 patients showed left ventricular hypertrophy and normalization of left ventricular dimensions and function (Tables I and II, Figs. 1-4). LVFS changed from 15.0±5.2% to 39.7+5.4% (p<.0001), LVEDD from 6.6±0.6 to 4.6+0.6 cm (p<-0005), LVESD from 5.6±0.8 to 2.8 ±0.6 cm (p<-0001), PWTh from 1.1 ±0.1 to 1.2±0.1 cm (NS), R/Th from 3.1 ±0.5 to 2.0±0.4 (p<.005), IVSTh from l.2±0.3 to l.5±0.3 cm (p<.05), IVS%Th from 14.2±4.1% to 28.5±7.8% (p< .005), PW%Th from 31.0±14.4 to 54.3±19.6% (p<.05), LA from 4.6±0.6 to 3.5±0.9 cm (p<.02).
Echocardiographic indexes of diastolic function were also studied by digitized M-mode echocardiography (Table III). PDVSE changed from 2.3 ±0.3 to 4.3 ±0.7 cm/s (p< 0.005), PDVPWE from 6.2 ±1.1 to 6.4 ±1.4 cm/s
(NS), PTVS from 2.3±0.5 to 3.9±1.0 cm/s (p<0.05), PTVPW from 3.7 ±0.9 to 4.9 ± 1.4 cm/s (NS), PFR from 6.7±1.6 to 9.1±1.4 (p<0.05).
We have compared the values of diastolic indexes in our patients with those of a group of 7 normal subjects and with those of a group of 15 "idiopathic" DCM patients (Table III). No significant difference was found between indexes in patients with idiopathic DCM and those of our subjects with systemic hypertension in the dilated phase, nor between indexes obtained in normal subjects and those of our patients after normalization of left ventricular function.
Obviously, the small group of subjects require further investigation to confirm our results. The blood pressure values of the 6 patients during the follow-up between the first and the second (or the third) echocardiogram are shown in Table IV.
FIG. 1 From left to right, two-dimensional echocardiographic diastolic (D) and systolic (S) parasternal long-axis views in three serial echocardiograms in one case (CG, 26/F). Left: the left ventricle (LV) appears dilated and poorly contracting. Middle: remarkable reduction of left ventricular dimensions and improved left ventricular function. Right: significant left ventricular hypertrophy with normalization of left ventricular dimensions and function. RV=right ventricle, LV=left ventricle, LA=left atrium, A0=aortic root.
FIG. 2 From left to right, two-dimensional echocardiographic diastolic (D) and systolic (S) apical four-chamber views in three consecutive echocardiograms in a different case (SR, 38/M). Left: dilated and poorly contracting left ventricle. Middle: mild improvement of left ventricular function. Right: the appearance of significant left ventricular hypertrophy and normalization of left ventricular dimensions and function.
FIG. 3 From left to right, M-mode echocardiograms in two subsequent examinations of another patient (BP, 57/M). Left: dilated and poorly contracting left ventricle. Right: significant left ventricular hypertrophy and normalization of left ventricular function and dimensions.
FIG. 4 Two-dimensional subsequent examinations of the same patient as in Figure 3. Top: Prom left to right, apical four-chamber view and parasternal short-axis view at the level of the papillary muscles in diastole (D) and systole (S) in the first echocardiogram. The left ventricle appears dilated and poorly contracting. Bottom: From left to right, apical four-chamber view and parasternal short axis view at the level of the papillary muscles in diastole (D) and systole (S) in the second echocardiogram. This examination shows left ventricular hypertrophy with normalization of left ventricular dimensions and function.
A dilated and poorly contracting left ventricle can be due to a "primary" ("idiopathic") dilated cardiomyopathy or can be "secondary" to a well-known cause.[1-3]
Lam et al. reported one case of reversible dilatation of hypertrophied left ventricle in pheochromocytoma, documented by serial two-dimensional echocardiographic observations. Reversibility of dilatation of the left ventricle in long standing chronic systemic hypertension has been thought to be less likely to occur, and to our knowledge has not yet been documented by echocardiographic studies.
From our study, it appears that left ventricular hypertrophy and normalization of left ventricular dimensions and function can be documented after adequate medical treatment in selected patients with long-standing chronic systemic hypertension and echocardiographic features of dilated and poorly contracting left ventricle. It is conceivable, in these cases, to classify left ventricular dilatation and poor left ventricular function as secondary to the hypertension itself and to suggest the hypothesis of a cause-effect relationship between therapy and normalization of left ventricular parameters with findings of left ventricular hypertrophy.
The dilated and poorly contracting left ventricle, which we observed at the first echocardiographic examination, could be due to "afterload mismatch".[5,9,13] In fact, repeated and/or prolonged increased afterload could lead to left ventricular dilatation, which can be considered as a "preload reserve," aiming to preserve an adequate stroke volume.[1,9,14] When the maximal limit of the "preload
reserve" is reached, further increment of afterload could cause reduction of LV function and decreased stroke volume. This condition may not be necessarily associated to depressed myocardial contractility. As reported by Gunther and Grossman, in aortic stenosis, poor cardiac performance could be due to inadequate hypertrophy or inappropriate geometry. This could happen even in dilated and poorly contracting left ventricle associated with long-standing chronic hypertension, such as in our cases.
Our cases may then represent "inappropriate hypertrophy with high stress",[6-9,13,15] that is excess dilatation out of proportion to left ventricular mass.
Left ventricular function in hypertensive heart disease depends significantly on heart size and, with similar systolic pressure, on the systolic stress which is imposed to the left ventricular wall. Patients with high stress hypertrophy and dilated left ventricle have limited stress reserve but high responsiveness to cardiac unloading interventions.
By reducing afterload, blood pressure normalization is achieved, probably allowing the left ventricle to "reassume" the hypertrophic condition due to systemic hypertension and pre-existent to the development of left ventricular failure.
This study is retrospective, and only selected cases are reported. For these reasons, we feel that further experience is needed to clarify the prevalence and to understand the physiopathology of the findings we reported. We think, however, that findings of left ventricular hypertrophy and normalization of left ventricular dimensions and function in patients with long-standing chronic systemic hypertension and previously dilated and poorly contracting left ventricle are documented by our data. These observations may have relevant prognostic and therapeutic implications.
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KEY WORDS: two-dimensional echocardiography, cardiomyopathy, systemic hypertension.